Perhaps it did not ruin your day. Perhaps the thief did not ruin your day but you consciously let the thief/theft ruin your day. I am not saying to pretend nothing happened, but this theft is nothing more than an instance of revealing human nature, revealing that all of us have bad tendencies, do bad things, take bad actions. And since this is man/womankind's basic nature, then it is, in essence, truth--men/women doing exactly what they are capable of doing; in this case, bad; in other cases, good.
Acknowledge the incident occurred--yes; however, to throw away a good and turn it into a bad day, strictly because of you chose to respond to the theft is not only your responsibility, it was your chose.
The Camino is the larger issue and the larger focus; your pilgrimage has not been stopped; you will still continue; you will still reap the overwhelming benefits. This theft does not deserve credit for ruining your day. It is too miniscule an incident to warrant same.
All the same, I wish the theft had not occurred. And my sympathies to you in this regard.