This comes from the book Letting Go by David Hawkins, M.D..
It is the accumulated pressure of feeling that causes thoughts. One feeling, for instance, can create literally thousands of thoughts over a period of time. Think, for instance, of one painful memory from early life, one terrible regret that has been hidden. Look at all the years and years of thoughts associated with that single event. If we could surrender the underlying painful feeling, all of those thoughts would disappear instantly and we would forget the event.