eli5: Why do we always get strong urge to be lazy if its better for the brain to be active

Question

I mean its so much better for the brain to be active working doing useful things stimulating your brain or working out, we all have a reward system and everytime we finish a task we feel a sense of accomplishment but everytime you should be doing something that you know will feel good in the end you just get this urge of doing nothing today and just relaxing,
shouldnt our brain be chasing this sense of accomplishment? Where does this feeling come from

In: 7156

Answer 1

Even when we’re “just relaxing” are we really not doing anything? My kids, when they’re “doing nothing” are either doing artwork or playing video games or watching movies. All those things are stimulating on some level.

I used to play a lot of video games, but recently I watch movies, read Reddit, cook and do things around the house. None of these are true idleness, in the old-fashioned sense.