I like the visual of a small pebble creating the ripple in a still pond in describing the kind of impact one moment can create. When I think back to the people who did something, wrote something, said something, encouraged something, or listened to something in my life that created impact, I think of how many ripples before them and the expanding ripples after them (and me) are yet to happen.
When your name is mentioned in a conversation; when "credit" is being given to you about something; when an action or deed is recognized; all these moments are invisible to you - most even after you leave this world.
I think when you are in Heaven, you will suddenly see, hear and experience all those comments of others (a sort of Ebenezor Scrooge moment with the ghosts of time) and know all the impact moments.
What seems small and invisible to you today - will be infinite and known in eternity.