Sorry, I think I didn't express myself right. I know that you need the private key to access the coins. This is what I have meant:
I read some cases on Reddit where users forgot about their wallets filled with lots of Bitcoins and find it again years later. Maybe this is also a similar case.
It's not. If they've lost the coins the public address doesn't matter.
I'm confused
I don't think you're the only one. It seems the OP has found a public address with 500 coins in it and somehow thinks he's found some lost coins or something. He thinks because he's found it he can tell the owner about it and give him his coins back. Or maybe not haha.
NO, I cannot give him back any coins of course - I neither have the private key to this public address nor I have access to his wallet file / his coins / whatever!
1. I read some old bitcointalk.org forum posts
2. In a pretty old thread, I found a public address from an old Bitcoin user named "justmoon"
3. I was curious if the user was still using his address
4. Checked it on blockchain.info, found out that the address is linked to almost 500 BTC, unused since 2011
5. Was interested in who the owner of these BTC is
6. Did some research, found it out
7. Trying to contact him for interest, just to see if he intentionally hoards so much coins since years or if he just forgot about the coins