Technically if it happens in 21 years your 100% confident prediction is wrong. You'd still feel you kinda got it right, though. Certainty is a different beast.

Technically if it happens in 21 years your 100% confident prediction is wrong. You'd still feel you kinda got it right, though. Certainty is a different beast. Not even "Tomorrow the sun will raise in the morning" can reach 100% certainty.