He uses the memory to drive him to more success.
Arizona Cardinals defensive tackle Calaias Campbell was a guest on ESPN's show, "Highly Questionable." They frequently have all sorts of interviews and it was Campbell's turn. This video clip from ESPN is where he talks about growing up and having to live for a time in a homeless shelter.
There were 10 people in the one-room living quarters, but he said it was better than living on the street.
He continues to use the experience as something he thinks about now that helps him work toward more success.