One of my buddies plays a mean rhythm guitar and some bass (on his own home studio recordings) picked up and tried playing my fretless the other day. Took him ten full minutes to figure out why the intonation was so horrible - he mistook it for a fretted one.

I tried to make him feel better by telling him how I once checked out a guitar and was dumbfounded at how awful the chords sounded - till I realized it was a lefty....
