I noticed recently that I have the most difficulty being patient during transition periods, that is, during the last stages of something.
The last few minutes before a plane takes off, after everyone is in their seats with their seat belts buckled. Why aren’t we in the air yet?
The last ten minutes or so of a meeting. All the business is finished, why is there chit-chat instead of adjournment so I can leave?
Waiting for a check at the end of the meal in a restaurant. They cleared the dessert dishes away, why aren’t they bringing the check?
As I was reflecting on this (having noticed my impatience during the interim between the time my plane landed and the time we were permitted to disembark), I realized that my impatience in situations like that has to do with the fact that I’ve mentally already moved on to the next thing. My mind says, this event/experience is over and so time between “over” and the beginning of the next thing is wasted time.
As soon as I articulated that to myself, I could see the problem: the unstated assumption behind my impatience is that nothing in the present moment could possibly be worthwhile. Of course there could be something quite worthwhile, and the lack of mindfulness inherent in my impatience would make me miss it.
My resolve: to try in such situations to stay in the present moment. To let go the idea that it is already time for the next thing and to stay with the present thing until the end.
Creo en Dios! 
I thought of this posting the other day as I pulled into the parking garage. The person in front of me didn’t know what she was doing, slowly pulled the ticket (whereas I had a quick-scan card due to contract parking), and then ever-so-slowly drove up the levels of the garage with me fuming in my car behind her ready to get onto the “next” part (parking and getting inside). I thought of having patience in the transition and it certainly gave me something on which to reflect. It was useful then in calming my temper, but also helping me to recognize some of the larger ways in which I miss something due to deeming it an unimportant transition.