How did I end up with a nick like Mr. Muskrat?

My first name is Matthew but ever since I was little, I have simply called myself Matt. My tale begins when I was in the fourth grade. The other boys kept trying out new nicknames for me. Matt Dillon, for example. One day, someone called me Matt the Muskrat. After a while, they shortened it to simply Muskrat. (My last name is Musgrove, BTW. Several of my relatives tell me that they too have been called Muskrat.)

Several years later, I started telling people my name was Muskrat, or I'd say my name is Matt but you can call me Muskrat.

So when I started hanging out online, I just kept on using Muskrat. On IRC, I am ^Muskrat or ^Muskrat^. I joined The Knights Who Say Ni! Seti@home team and chose the nickname Sir Muskrat for the message board. When I signed up here, I also choose Sir_Muskrat (I didn't know that you could use spaces).

Then one day at work, I tried to sign in and I couldn't remember my password! What to do!? I simply signed up for a new account with the nick Mr. Muskrat. I have been using this account ever since.