I had one. In 1981, I read a story of his that I have never forgotten, and I asked him for any details he was willing to share about the creation of that story.
The story was "Whatever Happened to the Crimson Avenger?" and it was a backup story in DC Comics Presents #38 (October 1981). I had never heard of the Crimson Avenger before, but the story pulled me right in. In the story, the aging hero is suffering from a terminal disease. He has one last chance to be a hero, by piloting a ship full of explosives away from people, and he does so, knowing that he will die in the ensuing explosion. Sadly, he forgets to give his name, so it looks like no one will remember him.
But...on the way to the ship, almost as a side note, he rescues a boy who has fallen out of an apartment window and returns the boy to his mother. As he swings away, he tells the mother his name. The story ended with the mother saying to her son that once he is old enough to remember, she will tell him of the hero who saved his life -- the Crimson Avenger.
Anyone who knows me well can understand why this story has stuck with me all my life. I must have read it dozens of times. So back in 1996, when I had a chance to meet Len, I told him how the story had stuck with me for fifteen years, and I thanked him for writing it.
And now, in his post Freefall in Crimson, Len has regaled us with the story behind the story. He doesn't explain where the theme of the story came from, but he does discuss how he worked together with Julie Schwartz to create that tale. Go read; you'll be glad you did.