In general “should” is just shorthand for “this is a better choice for me than the opposite”.
I think it’s more complicated than this. In my experience many shoulds come from social pressure, so “I should do X” is often implicitly something like “if I don’t do X then the tribe will disapprove of me,” e.g. I should exercise, I should eat well, I should study, and so forth.
I think it’s more complicated than this. In my experience many shoulds come from social pressure, so “I should do X” is often implicitly something like “if I don’t do X then the tribe will disapprove of me,” e.g. I should exercise, I should eat well, I should study, and so forth.