I often play Nethack as a monk, so wisdom is a fairly important attribute. Occasionally I will see the message:
You feel foolish! You haven't been paying attention.
...which means my wisdom has decreased. The trouble is, I usually get these messages while I'm just walking around, so I haven't been able to match the wisdom decrease to a particular action or behaviour so far.
The wikis are a little vague on what, exactly, abuses wisdom. What could I be doing to trigger this?