To be honest it's probably as illegal as clicking "Save As..." on a website picture of a cute puppy or kitten, where you haven't asked ahead of time for permission.
But you were 12. And you did buy a PS1 unit. Sony got something from you. You then played these pirated games and got into the hobby. Chances are if you could only get legit games you'd not be the enthusiast you are now and Sony or other industry members would not be making cash from you right now. Nor would you be providing free marketing for their products by among others, these forum posts.
There was a shop in Mayfair and a guy in Roshnee that used to sell fake games for PS and Xbox. Don't know if they are still around. The guy in Roshnee used to advertise via a newsletter that was sent to certain people.
As to it's legality, It's definitely illegal.