I disagreed to an extent--I'd always tried to be careful not to try to influence their children in any particular direction, because I didn't think it was my place to do so. And there were other influences in the kids' lives that could have pushed them in certain directions as well that certainly had nothing to do with me. Not that it is bad that their daughter is how she is, but I don't deserve full blame/credit/whatever you want to call it.
The parent wrote back to me that whatever I said or didn't say, it was how I behaved that counted the most--so much so, that they think that it's still influencing their daughter so many years down the line. Then the parent wrote what really made me smile from ear to ear:
"And another point: One of our best decisions as parents was to open our home to you at a time when we were all very impressionable. That's one decision we'll never regret!"
I feel like that's one of the highest compliments someone could have given me--that just by being around, I changed their lives for the better. Because, in truth, it was they who were doing me the favor. It just gave me warm fuzzies to hear it, and I wanted to share. :)