Id recommend joining as well. There is nothing better than working in a field you enjoy and want to work in, especially in the technical fields, where the presence of desire and motivation can make the difference between an average engineer/scientist/doctor and a really good one.
In any case, the sort of experience you will gain in the paf will make you very marketable in the private field as well, if you decide after a few years that it is not what you want to do.