What happens to us is that we identify ourselves with our experiences. We hold on to what has happened. This is how wounds are created and through our memory these wounds come up to affect us.
There is a very well known Zen story that shows very clearly the process of holding onto these experiences. Two Zen monks were walking together, and they came to a place where there was a stream. There was also a girl there who could not cross the stream by herself. One of the monks lifted up this girl and carried her across the stream. Then he placed her down and they continued on their walk.
The following day the other monk said: “You know, you should not have touched that girl, you should not have carried her across the stream. We are monks and we are not supposed to do that.” Then the other monk responded: “I left her on the other shore, but you are still carrying her!” This is what we are doing, we are carrying things we should have put down, so it is very interesting for us to know what we are carrying.