I have a similar story without the happy end. A friend of mine remind that he bought 20 BTC years ago just for fun and forgot about it, he remind about it one evening when I was talking about Bitcoin and what success it reached, and he was like: "hey man, I have some, but I don't even remember where it is blah blah"
If he used an online web wallet there is maybe a thing to do to get access again to it. He may be able to identify where the wallet is hosted with Walletexplorer.com Once he find where it is, he may be able to reset the password via email. Once it's done boom, he get the bitcoin back.
For 20
BTC it's good enough to spend some time to try