Very strange. I tried to log into my Steam account a while back and couldn’t remember my password. Unfortunately my recovery email was also so old that I didn’t have my password for that either. I recall talking to Steams help desk and they wanted card details of the card on file but I knew for a fact that it would have long expired so I couldn’t provide that either, so the account was lost.
I say very strange at the start of this post because I’ve visited the Steam website just now and my iPhone suggested a saved username and password. Well what do you know… I’m in! And all of my library is there 😬