This week Puzzling SE turned 10 years old. Congratulations on asking, answering, voting, and building this community for a whole decade!

Whenever a Stack Exchange site turns 10 we like to celebrate by encouraging users to reflect on their experiences here.

How did you first discover the site? Do you have a favorite puzzle, a particularly ingenious solution, or something that taught you something new about puzzles? Any funny anecdotes or other insights on your time here, that you would like to share? We want to hear it all!


4 Answers 4


For me, the highlight has been asking/viewing (what I thought were) unrelated questions, only to have them all solved by Rob Pratt and his signature phrase:

The problem can be solved as follows via integer linear programming:

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    $\begingroup$ puzzling.stackexchange.com/… $\endgroup$
    – ACB
    Commented May 17 at 15:58
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    $\begingroup$ I have to say that I would find those answers even better if Rob also explained how the original question is formulated as an ILP problem. (It's usually not difficult "for one skilled in the art", but not everyone is. He could just copy-and-paste his code...) $\endgroup$
    – Gareth McCaughan Mod
    Commented May 18 at 10:49
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    $\begingroup$ Three cheer for this! I've actually applied constraint programming techniques I learned here from Rob Pratt in my mathematics research. $\endgroup$ Commented May 18 at 22:03
  • $\begingroup$ ILP still boggles my mind $\endgroup$
    – JLee
    Commented Jun 3 at 19:16

Oh, this is a fun milestone!

What a ride it's been ...

I joined PSE on 13 November 2014, having seen this answer from the HNQ list. This was at the height of the massive spike of activity in the form of many puzzles of questionable quality, also known as the days of the spaghetti parties. In real life, I had unusually much spare time that week, and after being inspired to create my first-ever riddle, I decided to join in with gusto and spend the week (yes, just the week) having fun on Puzzling SE. Little did I know that I'd still be here 10 years later!

The huge increase in activity and decrease in quality led to a dramatic split in the community in Nov-Dec 2014, a period which I refer to as the GPW or Great Puzzling War. The less said about that, the better, but the drama around TMBMP (The Mods' Big Meta Post) dragged me into participating a lot more, in the meta/chat/community side of things as well as just posting Q&A and comments, which was all I'd been doing up to that point on other SE sites.

In 2015, I'd become less active after the dying down of the GPW, when, not entirely by my own choice, I became the site's highest-reputation user, and suddenly felt more pressure to live up to that. Thereafter, my reputation graph tells its own story: spikes of activity punctuating periods of stagnation, while at the same time becoming a highly active user and moderator on other SE sites.

Puzzling will always have a special place in my heart, though, as the site that brought me into an SE community rather than just seeing it as a site to get answers to some questions.

Favourite puzzles, oh wow ... there's so much to choose from. Luckily, I've already sort of answered this on main meta, so I can self-plagiarise from there:

  • $\begingroup$ Yeah, I posted some pretty bad/mediocre puzzles at first, but slowly learned from all the great feedback what makes a good puzzle and what doesn't. I remember you back then Rand, super-optimized for point grabbing. I say that as a compliment in most cases. At any rate, it truly is a great venue, and I'm glad I stumbled across it in 2015 ish, even though i took 7 years off at some point. $\endgroup$
    – JLee
    Commented Jun 3 at 19:15

Well, apparently for at least a short time after I answer, I'll be the user who joined the earliest (30, May 2014). Although I didn't answer a question until the end of July, so I wasn't paying a ton of attention right away.

I suspect that like many people at the time, I found it while attempting to get some work done using Stack Overflow.

My favorite puzzle, at least that I answered, was The frog concerto, mostly because of the praise from OP for my answer.

However my absolute favorite thing was when a package showed up at my house with a t-shirt and a thank you from Stack Exchange. (Do they still do that for new sites?)

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    $\begingroup$ You'll probably keep that title of being the earliest user among the answerers here. We don't see many 3-digit user IDs nowadays. $\endgroup$ Commented May 22 at 12:26
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    $\begingroup$ Funny how long I've been on these sites and never noticed the user IDs, and now I'll never not see them. $\endgroup$ Commented May 22 at 13:47
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    $\begingroup$ wait, i'm 463. That means I joined before Rand!? I must have not been active til way later $\endgroup$
    – JLee
    Commented Jun 3 at 19:18


I was already a bit interested in puzzles back then, so I visited several puzzle websites. Then I stumbled upon this in late 2018, spectated, made an account in mid-2019, and started to use the site more after the pandemic's lockdowns took effect.

I was introduced to a variety of interesting puzzles I had never seen before. One of them was the cryptic crossword/cryptic clues genre of puzzles. @Jafe had made many such crosswords before, and me being the clueless newbie that I was always looked at the answers without attempting to solve them. After a while I realized it was an interesting puzzle (since I like wordplay) and wanted to try solving them more. (But I am not an expert - I still have to get to the point where I can solve them without getting aid from the Internet frequently!)

Any lessons learned?

I think the site teaches me one important thing about puzzles: the solution path, which is the path to get to the puzzle's answer, should be unambiguous. The puzzle should be crafted such that there is only one correct way to extract an answer, and all other ways which seem like they lead to the answer will turn out to be clearly wrong. In other words, it should be true that the answer the solver found is correct if and only if their solution path is correct (and equivalently, the answer the solver found is wrong if and only if their solution path is wrong). But of course, in practice, doing this is not easy.

An example of this is my entry for the 2023 PSE Advent Calendar. If you look at @sean47's solution, you'll see that he found the answer to the puzzle but in an unexpected way. But no matter how "absurd" his solution path may seem to me, it doesn't matter since that is absolutely not his fault; the fault is mine. Since the answer he found was clearly correct, then why would his solution path not be? Of course, this thinking is not logical, but it would not be satisfying for a puzzle to have multiple solution paths or multiple answers which are not deliberate. (To be honest I don't know how to justify this further, but I guess that is just how puzzles work, for me at least.)


I'll admit that my passion for puzzles isn't as huge as that of others; nonetheless I still like seeing and solving them, and I don't regret exploring this site.

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    $\begingroup$ While this answer is almost a week late, I didn't want to post at first since I anticipated that many people would answer. But before me there were only two answers, so I thought to add my piece now. (And as a side note, for those curious with how cryptic clues work, I think Deusovi's cryptic clue guide and Wikipedia's article on cryptic crosswords are good introductions.) $\endgroup$
    – oAlt
    Commented May 21 at 10:46

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