Simple : Something like more than 10 years ago I was at school and wanted to register on some website. I had no internet at home and my computer was probably still the 486 DX2 66MHz so no luck getting internet on that anyways. So I wasn't realy knowing the internet "rules" and just entered my name in the "Username" field. It said me "Nope, Arnold is already used, you can chose in between these 3 choices" and Arnold0 was one of them. I had no imagination back then, and I still don't. It would be very wierd for me to be called by something else than my name nowadays (The only exeption being Arnlol, because Arnold0 was already used on Youtube and Twitch...). Whitin these years I've had people calling me ArnoldZero, but also some calling Arnoldo. Most of the times, people just call me Arnold now which is better.