So did I, but still didn't get that high before the wastelands; Wisdom will only give you an extra one or two levels, anyway (
Wisdom - is it worth the skill points?). I also left the wishing well and the imp council member until late, to get the most benefit from the bonus level increases.
Did you start off doing a lot of killing, and leave many of the quests until later? That could account for some of the difference; killing enemies gives you more experience when you are at a lower level than them, while quests give more experience at higher character levels.