It's not that I don't believe you, its just that in 2010 about the only way to generate a bitcoin address was with the bitcoin client software. 8 words and passwords weren't really a thing as far as I can tell. bitaddress.org, brainwallet, paperwallets websites, online wallets etc weren't online in 2010.
I could be possible that whatever site you bought the bitcoin on sent you a pgp encrypted wallet file. I read that somewhere, but I have no experience in how any of these sites worked except for MtGox.