My days are filled with joy!

Filled suggests something continuous, and days rarely work that way.

What a good one actually contains is four or five minutes that were genuinely good: the first coffee on the step before anyone else is up, a message that made you laugh on the bus.

Those minutes are small and they do fill a day, in the way a handful of coins can weigh down a pocket.

The trouble is that they get spent without being noticed. Try naming yesterday's. If three come back, the day was fuller than the summary you gave it.