We need to do a quick lesson on possibility versus probability to tie up our worry section. Just because something is possible, does not mean that it is highly probable. Often, possibility and probability are confused with each other. Many times people see that the mere chance of something happening must mean that it absolutely will happen. This is, of course, not true at all.
It is possible that you will win the lottery today. The probability is very low, and zero if you do not play the lottery, but it is possible. Even though the probability is small, millions of people still play the lottery because sometimes someone wins, and it might just be them.
People with anxiety disorders will often use the same thought process and they will do something to undo a potential bad thing on the off chance that if they do not do it, then something will for sure happen, and it will be their fault. They may think that it really is no big deal to touch the door three times, since doing so will prevent the house from being broken into, and in the grand scheme of things, this will not seem like such a big deal. But, add up all of the small things that people do all day long to try to stop some stressor or to prevent something that is anxiety provoking from occurring and you can get hours and hours of daily rituals that people are locked into because they feel as if they have to do them in order to prevent something bad from happening.
Take this example: Write down on a piece of paper the following quote: I hope that a meteorite hits me today. Then, carry that piece of paper around with you all day and see if it actually happens. Probably not, but it is possible. Tomorrow, do the same thing, this time write on the paper: I hope ___________ gets hit by a meteorite today. In the blank space, write the name of someone that you love.
This may be a bit harder to do because we think that now, if it does happen, we will be responsible for it, and yet the possibility and the probability of it occurring did not actually change. What did change is our thoughts about it. We may say that it is OK to think this about ourselves, but if what we do might affect others, then it is not at all acceptable. But, if what we write down changes its possibility and probability level based on if we write it about us or we write it about others, then there is magic that is involved. In psychology we call this Magical Thinking - the belief that our thoughts will make things happen or will make things come true. While this is popular in pop-psychology, those of us who are research based know that this cognitive distortion can do more harm than good - it can lead you to believe that you must think of certain things in certain ways or you will be responsible for bad things happening. This is, of course, not at all true.
So, recognize that just because something is possible does not mean that it is probable. You can worry all you want about all sorts of things, or you can get out there and live your life. As for me, I think about when I get to the end of my life, which could be tomorrow, or could be 50 years from now. I would want my tombstone to say, "He lived a life of good times, happiness, and adventure, and loved working with his patients and co-workers every day." That is sure better than, "He stayed home a lot worrying about all of the things that could have happened to him, therefore dying alone with little adventure to speak of."