On my first college field trip out of the country, my dad booked airline tickets online for me (I didn't have a credit card then). The password he put on them so I could collect them at the airport was "Rockhound" - my dad has an odd sense of humour and I suppose that it must have been funny at the time, seeing as I was a geology student.
Anyway I thought just plain Rockhound sounded wrong, and I was mulling over what else I could use when it occurred to me there was no sign of any other Irish posters on EvCForum. So IrishRockhound sounded right.