I don't like writing 15 characters, so my signature is a scribbel. Even better that it's impossible to forge unless someone's a doctor.
My last name could have been even longer. If my surname wasn't changed a few times it would have been O'hUallachain.
Hey, if I insisted on using my Irish name I'd be Áine Mhaire Ní Choncubhair. People can't even pronounce that! *LOL*