Andrew Wyeth's father, N.C. Wyeth died in an accident just as young Andy was establishing himself as an artist. As Andrew (1917-2009) recalls in this rare interview, filmed at the time of his 80th birthday, he never got around to painting a portrait of his dad, even though N.C. was a very important figure in his life.
(Video link) "I made drawings of him, but nothing important, and I think that was a great tragedy of my life when he was killed, that I hadn't done it. It changed my whole outlook on portraiture for me personally. When you know something, and feel it, and have a love for it, my God, do it. Don't let it go by."
Andrew Wyeth on Wikipedia