The other thing I found helpful is I think it's L3 by default does lock on target, but it's also dismount from your chocobo. So normally you're riding the chocobo, hit L3 and you hop right off. The problem I was having was if an enemy targets you or tries to attack you while you're on it, pressing L3 would automatically lock on target on that enemy, instead of jumping off the chocobo. So you'd have to press it again, then circle to deselect that target, and THEN L3 to get off the chocobo. There's a setting in the options, can't remember where as I'm not on it now, but you can change L3 so that it only dismounts or whatever it is and doesn't lock. I've never used auto lock, so that was a huge help for me since now anything can target me and I can hop off the mount easily.