Comment by parpfish
I spend too much time thinking about all the stuff that can go wrong on generation ships.
You take off for your destination, but when you get there you find out that humans back on earth made a faster ship 100 years after you left and beat you to the destination.
You spent generations expecting to be bold explorers pushing the frontier and getting to claim nice territory, and you show up to find you’re in second place.
I won't spoil it here, but you might really enjoy Chasm City; I recommend giving it a read. :)