It's not what youryou are, it's what you don't become that hurts.
(Oscar Levant, pianist, composer, author, comedian, and actor)
Regret for the things we did can be tempered by time; it is regret for the things we did not do that is inconsolable.
(Sydney J. Harris, journalist)
Maybe all one can do is hope to end up with the right regrets.
Arthur Miller (playwright)
A man is not old until regrets take the place of dreams.
John Barrymore (actor)
For of all sad words of tongue or pen, The saddest are these: 'It might have been!
John Greenleaf Whittier (poet and abolitionist)
Every man is guilty of all the good he didn't do.
Voltaire (author)
I regret that it takes a life to learn how to live.
Jonathan Safran Foer
Regrets are the natural property of grey hairs.
Charles Dickens
A man is not old until his regrets take the place of his dreams.
Yiddish proverb
The first half of life is spent in longing for the second, the second half in regretting the first.
French Proverb
One doesn’t recognize the really important moments in one’s life until it’s too late.
Agatha Christie
Does any of these suit?
How did I find these? I googled
regrets proverb
As you can see, I got a pretty good harvest. But some of the phrases that turned up were totally useless. Best example of this: "I regret to say that we of the F.B.I. are powerless to act in cases of oral-genital intimacy, unless it has in some way obstructed interstate commerce." -- J. Edgar Hoover