I had an amazing day, but I shouldn’t want it again?

My mood was the best it’s ever been in the past 6 months. The worst could’ve happened and it wouldn’t have bothered me as much.

My coworkers thought I was in a bad mood cause I was so quiet but I actually felt centered and focused and only spoke when necessary.

These kind of days are few and far in between. Why is it bad to try to repeat this? I’m not attached to this but why is bad to WANT to feel positive again?