I recently moved from the Washington, D.C. area (Tysons Corner) to a city just outside of Charlott, NC.
Moving companies are expensive, so I decided we would pack everything up ourselves and drive 6 hours to our new home. Over the past 9 years, my family has grown a bit, so we needed one of the larger moving trucks.
When I pulled into the lot to pick up our moving truck, I was a little intimidated by how huge the moving trucks actually are. When the guy in charge handed me the keys, he asked if I was alright driving the moving truck. He seemed to be in a hurry, and I was in a hurry to get home, so I said, "Yep!"
I couldn't believe I could just walk in and start driving that thing.
During the drive I had lights flashing and buzzers buzzing - I didn't know what was going on. Everything turned out alright, and I ended up being a pretty competent driver, but upon reflection I think next time the guy at the counter asks whether I'm okay to drive a 22' truck, I'm going to say, "Why don't you give me a few pointers."
When you ask your users whether they're alright navigating around and doing something new, you'll often get the response, "Yep!" If I were you, I would trust, but verify.
Ask them to perform a few tasks - not as a quiz, but more of a "Great! I'm glad you're so smart. Let me just give you a few pointers for getting around some tricky spots."
Otherwise they will end up calling for help from a Denny's just off I-81 because they don't understand what they're doing (that may or may not have happened to me). It's better to prepare them ahead of time before they make a mess of things.