Typically I feel as though I'm a patient person. I can remain on hold if needed, sit in the doctor's waiting room for extended periods, all while keeping a relatively cool head. But everyone has their limits, and my children often test mine.
Some say patience is like a muscle, that with practice you learn to conduct yourself better in times of waiting. If so, it may be the slowest growth muscle of the body. We all have to wait long periods at some point, probably several times a week. Yet it's difficult to improve your patience.
The only practical training, I think, is that moment before detonation. When your stamina has been spent and the un-dignified "you" is about to emerge, try to hold on just a little longer. We all fail at patience, but if we try just a little harder than we did last time, perhaps we'll be better off in the long run.