A "I can't believe what just happened" moment

Have you ever had one of those moments where you thought, "I can't believe what just happened" or "I can't believe what I just saw?" I'm not talking about watching a video replay of an event like the space shuttle blowing up, or the attacks on 9/11. I'm referring to something that happened in the moment--and it was amazing.
I was reflecting on one of those moments recently. A little background first. It all stemmed from an issue I had with my left knee . . . in Mexico . . . on my Mormon mission . . . in 1989. (I wrote it that way for dramatic effect) Now when I say issue, I'm talking about me, my bike, a car and an incident that caused me from being able to bend my left knee. (That's a whole other story--heck, I may even write a book about the experience)
This story picks up when it was determined that I needed to have surgery. I was to fly back to the USA from Mexico. I was able to walk with the help of a crutch. It was one of those metal ones that had an inch of foam at the top for padding, a rubberish like handle and a rubber cap on the end.
To get to Utah from the Yucatan, I would be taking several shorter flights. The itinerary had me flying from Merida, Mexico to Mexico City to Mazatlan, Mexico to Denver, Colorado and finally to Salt Lake City.
We landed in Mexico City around 10ish in the morning. I was to have about a 2 hour lay-over there. However, I had a bit of an issue. First, I had two suitcases I need to take from one side of the airport to the other, and I was only able to walk with the use of my one crutch.
I remember standing at the gate with my suitcases (we were on a small plane so there was no going to baggage pick-up. We were given our suitcases when we got off the plane) and wondering "What the heck am I going to do?"
A kind gentleman from the airport spotted me and offered to help me get to my next gate. To get there, we had to go through the metal detector. Now remember, I am using a metal crutch to walk. Once I get to the detector, I go to hand them the crutch with the intention of hopping through on one leg. They insisted I use the crutch to walk through. So I did. And the detector went off. So they had to pat me down and use the "magic wand" to make sure I wasn't packing heat or something like that.
I finally arrived at my gate. The man that helped me with my suitcases stood there with his hand open. Knowing that I wasn't going to be coming back, I gave him all the rest of the pesos I had on me aside from a few coins and one small bill (worth about 20 cents US) that I kept as a reminder of the trip. It was all the money I had on me--I didn't have any U.S. bills.
I still had an hour or so before my next flight and so I made myself comfortable as could be and waited. After twenty minutes or so, a man came up to me. He asked me if I was a missionary. (We weren't allowed to wear nametags in Mexico--I don't recall why) I said "Si" and then realized he asked me that in English, so I then responded "Yes." He stood there for a moment, a puzzled look on his face. He then said, "I don't know why, but I feel very prompted to give you $10." I thanked him for the offer, and told him I'd be fine. He was quite insistent, so I agreed. Out of habit, I put the $10 bill inside my tie to keep it safe. (That's where I kept my large peso bills when I was in Mexico).
Time passed and I was on my way to Mazatlan. I was actually served a meal on this flight, and with the clouds and angels as my witness, it was Spam. As we landed, we were told that everyone needed to get off the plane and go through some sort of check point. It was the next announcement that was one of those "I can't believe what just happened" moments. I know for a fact that my Heavenly Father was watching over me at this time. How do I know? Because we were told that at the checkpoint we would need to pay $10--and it had to be in U.S. bills.