Somebody taught you to read. It took months, it was tedious, and you have no memory of it whatsoever — yet almost everything you have done since runs on that one unrepaid favour.
A life is full of these. The teacher who pushed you into the subject you ended up loving. The friend who introduced you to the person you married. Whoever laid the road you drive on.
Blessings sounds grand until you break it into the specific people and accidents it is actually made of.
Pick one you can still contact and tell them. Most of them never found out it mattered.