Rejection - Mr T

How can someone get knocked back 197 times and not give up?   Now that you know a little about American 15 year-old Jack Andraka and his amazing breakthrough cancer technique, how do you rate his persistence? His confidence? His sheer strength of will?  What if he had given up?  I think a lot of adults (including myself) have a lot to learn from Jack.  He was able to bat away criticism that at best was ageist and at worst, dismissive because of lack of scientific credentials.  We have talked about many authors who have had manuscripts rejected by publishers (and some which have gone on to become successful and licences to print money).  What has been your greatest rejection?  What did you learn from it?  How do you process it?  Is it hard to accept?  How important is it to keep the big picture in mind?  Did you fight back?  How?  Do we need more Jack Andrakas?