Being a guitar player my most un-favourite instrument is the guitar as played by John Renbourne, Duck Baker, Charlie Byrd, Albert Lee, Brian May I could go on and on. These guys are so good no matter how much I practice I don't get close.
I also object to those kids you find in music shops barely out of nappies (diapers) who already play better than I do.
Makes you want to put the instrument down and quietly walk away. Though I haven't done so yet - think positive. After all I've only been playing for 20 years in another 20 I guess I may have got the hang of it.