Had my worst flat *ever* yesterday on a rental bike (Las Vegas):

- put the spare tube in the tire, it wouldn't inflate. I thought the problem was a bad valve, so I went back to the original tube.
- patched the original tube - patch didn't hold (I was in a hurry)
- patch #2 - success! mounted the wheel, but tire was losing air even before I took off. pulled the tube again, and found a 2nd hole
- patch #3 - success. mounted the wheel for the 3rd time, and took off.

This was not a 4-minute job.