The more you ride, the more you will learn the difference in the way they act when they are afraid of something silly as opposed to something that may endanger you both. When your horse acts UNCHARACTERISTICALLY afraid, it should cause you to think twice. Like getting off and double checking the mud prior to pushing them on. That is all I am saying. Trust their instncts a bit and listen to them. It will save you more often than not. I also am older and wiser, but a not a green rider. Yes, accidents DO ahappen, and they will, but the more you pay attention to your horse and tune in to both them and your surroundings the better you will be.