Started seeing a chap who was nicknamed Toasty. His mates started referring to me as ‘Missus Toast’, and when I started playing World of Warcraft I took that name for my first character. Ended up sticking with it, with the occasional ‘Mrs’ variation after getting married.
My high school nickname and original online nickname Riggers was based on my surname, but it did get a bit confusing because my brother got called it as well by his mates, as does my nephew.
Could be worse, I’ve got one mate whose nickname is ‘Peebz’, because fifteen years ago, when walking home, someone said, “What’s that squeaking noise?”. It was his shoes, but what he actually said was, “It’s the sound of my plastic bollocks rubbing together”. Henceforth he was known as Plastic Bollocks, or PB, or Peebs.