You learned something about the hot list today - many titles only make sense in the context of their site. In future, you can hover over the link before you click it. If the link is on worldbuilding or puzzling, you can expect that the question pertains to an alternate reality and decide whether you want to click the link or not, and if you do click it you'll arrive in the right frame of mind.
The only prevention would be to order all members of this site to adjust their titles so that anyone seeing them on the hotlist knows somehow that the question is a puzzle. That would be very confining for no benefit - anyone seeing them on the hotlist can know they are a puzzle by observing they were posted at puzzling.se.
A small number of users had no idea puzzling.se exists, and the hot list actually exists for just this reason - to expose all of us to other sites we might not know about. A cognitive scientist might answer that the small "jar" you experienced as you came to learn that p.se exists and what it is all about is just the ticket for locking that material into your brain. That even further lowers the incentive to force p.se users to choose suboptimal titles just to minimize dissonance for hot list users.