2001 Ford Focus

I recently drove my 2001 focus from Tacoma Washington to the Bay area in California. On the return trip it was very hot (upper 90’s) all the way home. The car never over heated and for the most part drove beautifully. However, when we had gone about 250 miles, I stopped for a short break. I parked in the shade and was out of the car for maybe 15 minutes. When I got in, it would not start. There was no click and did not turn over. I could not depress the button on the shifter so I assumed that it didn’t go all the way into park. I took off the brake and rocked the car to try to dislodge it, but to no avail at first, but finally got it dislodged and could shift into Neutral and Park, but still nothing when I turned the Key. I called AAA to come get me. The call took about 20 minutes and when I hung up I sat for about another 5 minutes, then decided to try to start it again. It fired right up like nothing was wrong. What was it??? On the rest of the trip I had no problem. Why wouldn’t it start? It has been suggested that while it was not overheating that the electrical may have been too hot. ???