Before you sleep, say one true sentence about the day you just had. Not a good one, not a bad one. Just true. “It rained.” “I was tired.” That is enough.
A teacher once asked his students a question and then answered it himself: every day is a good day. People have argued about that sentence for a thousand years, because it is obviously not true. Some days are terrible.
He did not mean every day is nice. He meant every day is a real day, it is yours, and it does not need a mark out of ten.
Which day this week did you write off too quickly?
A bad day is still a whole day, and it was still yours.