Edd,
I agree that staying in 2wd as a long as possible is a good strategy. It give you a lot of feedback about how the road or trail is. It gives you a chance to perfect your technique. Most people are anxious to "try out their 4wd."
The worse the roads and trails the more you need a shovel, a tow strap, a handyman, a come along, a winch, a deadman and whatever else you can find.
If you have "never needed 4wd" you have probably missed out on a lot of the good country out there. I have worked in every western state and gotten stuck in all of them. In Alaska there are no roads so we got helicopter support.