i have an 18 in Wisdom also, though i find it odd you always happen to have high rolls when it comes to your own stats >.>
The Cleric also has a Dex bonus of -2 and a Con bonus of -1. >.> And I probably would have rolled pretty high on yours too, but once the result was 22(rolled an 18 +4 mod) I decided it didn't matter, you'd already seen everything you need to.