Can't turn the key on 2001 Jeep Grand Cherokee

Just today, I tried to start my Jeep but could not turn the key. Not at all. Steering wheel not locked, tried that already. Any thoughts?

Asked by for the 2001 Jeep Grand Cherokee
Sounds like the lock cylinder has failed, But if you have a spare set of keys try that first
1 more answer
I have this problem often and just need to play with the key. Wiggle it around and move the steering wheel. I will engage eventually.