Are there limits to teshuva? There are stories of people who lives sinful lives and did teshuva at the very end and Hashem accepted them, but did they really achieve what they could have in this life? Didn’t they lose opportunities? Even if they are forgiven for their sins, how could they ever make up for lost time? At what point is someone unable to reach their original potential? 80 years old? 50? 30? How can such a person avoid being discouraged? Thank you.
On one hand you are correct that a missed oppourtunity and missed years can not come back. On the other hand we can not underestimate the tremendous accomplishment of thier internal battles with the yetzer hora, and the fact that at the end they won and got close to H-shem. It is not up to us to do the judging, but it is our job to look toward the future and try the best we can. We are in good hands, just keep on going and H-shem will take care of you.