Constantly craving new neurological stimuli has its limits and inherent dangers. If we constantly seek something new instead of exploring the familiar in greater depth, we run the risk of destroying something healthy.
But I think Judas and Peter had similar hearts, fallible human hearts like ours. I think the same doubts that plagued Peter were the same doubts that prevented Judas from coming back to Jesus and the other disciples. I think the same faith that caused Judas to return the money in repentance was the same faith that propelled Peter to weep bitterly and then wait in hope with the other disciples.