Finding one thing to be thankful for on a bad day is harder, which is exactly why that one counts double.

On a good day gratitude is a formality, since the evidence is lying around everywhere. On a bad one you have to go looking, and the looking is what does the work, since it pulls your attention off the track it has run all day. The one thing you find is not a repair, only proof that your view of the day was partial.

Try it tonight if today went badly: one specific thing rather than a category. The coffee, the message, the ten minutes that were fine. Do not try to argue yourself into feeling better about the rest, since that is a different and mostly impossible job.