The Hebrew word for patience is savlanut, which also means "tolerance."
This same Hebrew root also gives rise to words that means "suffer" (sevel) and "burdens" (sivlot). If we equate being patient with suffering, and patience as tolerating that which is not our will, we will have an easier time in difficult and unpredictable moments. Once we lose the ability to have patience, anger or intolerance bubbles up within us. It is at that lowest point when we experience those feelings that we have mistakenly assumed we are masters over all, and we shun the ability of the Master of the Universe to work through us in an unplanned moment or sequence of events.
The next time you encounter a situation which brings you to the brink of losing your patience, practice this simple meditation.
First, take a few deep breaths. Then, imagine a pine tree, one not larger than 5 feet tall with at least 30 branches that have offshoots. As you imagine this tree before you, take upon the task in your mind to gently pluck every needle from the branches starting from the from top of the tree. Work your way down all branches of the tree in a very methodical way in your mind - slowly and deliberately.
What this will achieve for you is a mental focus, lowering of your blood pressure, controlled imagery, and will lessen your sensitivity to the matter at hand. Guaranteed, the situation will become less urgent and more manageable.