Bruce Fwaaa
First day of boarding school, I was 13. A bunch of other kids were trying to guess my name. They knew it was 5 letters long and started with a B. Had various suggestions of Boris, Betsy, Betty etc. Then someone said Bruce, and at the same time, a kid called Raj was looking into a mirror, and went "Fwaaa!" impersonating Bruce Lee. The name stuck. The school also misunderstood my application form and was under the impression I was French. They thought I came from Paris, but in actual fact it was the Welsh county of Powys that they had never heard of, so assumed it was a typo.