Yes it is rare for a boy of fifteen, especially from a European country like Belgian(where Buddhism not well-spread) to want to become a monk. Furthermore, he has a mother who is supportive of him. However, even he had to face obstacles like an uncle who was dubious about his knowing his own mind at a such a young age. Giel's uncle even had the court investigate his case. Eventually the court granted permission for him to go ahead.
He left for India after a six months delay, as certain as ever of his wish to become ordained. Here is clear evidence of the tremendous merits that Jiel must have accumulated for him to want to become a monk at such a young age and for him to have an unusually supportive mother.