A neighbour drove you to the hospital at night.
A colleague carried your work for a week while you were ill.
Lily cooked at the volunteer kitchen three Saturdays in a row.
You said thank you. A month later only the two of you remember. A year later, maybe no one.
DzenQ leaves a trace. You write a few words and sign, and the person keeps a letter: who is grateful to them, when and for what. And you keep a journal of who you're grateful to.