Well, you don't have to "unlearn" it. It's actually a good thing you went through the "pain" of learning it pre-ARC because if you understand how reference counting actually works, you will be able to make better and more informed decisions on the management of your objects in 5.0+ with ARC (e.g. when to use strong vs. weak properties). There's nothing magical about it, and Ray Wanderlich has a fantastic ARC tutorial that helped me greatly: http://www.raywenderlich.com/5677/beginning-arc-in-ios-5-par...
Holding off on ARC is only advantageous if you need to support iOS versions before 5.0, but ARC is the future of iOS.
Holding off on ARC is only advantageous if you need to support iOS versions before 5.0, but ARC is the future of iOS.