In PvE, the actual monking bit is too easy. Just when the whammos starts leeroying and getting out of range, then shouting for res and after all that blame it on you, THEN it gets irritating. In PvE, monking is more of an emotional test rather than about your personal skill level.
Whereas in PvP, monking actualy requires you to think. Even if you start in Arenas you will quite quickly learn to play when you have a e-denial mesmer, condition ranger and a KD war on your ass
Ofcourse in higher level PvP you will have to learn how to coordiante with your fellow monks, avoid over-healing and handle pressure, spike builds and such.
Enjoy!