the idea that one can be constantly happy or constantly miserable is also false. Life follows a cycle where things feel bad, then good and then bad again and so on. How much worse or how much better each of these stages in the cycle feels is completely random, sometimes you will only feel 5% better or worse meanwhile other times you can feel as much as 70% better or worse. How long each of these stages lasts is also completely random, you could feel so bad that it's as if death's hand is on your shoulder for months on end, or things could be cycling rapidly throughout the day which can be pretty disorienting.