Today the options for a young JW's spiritual career are:
1) Serve at Bethel doing, most likely, something very menial.
2) Knock on doors 70-100+ hours a week.
3) Knock on doors 50-70 hours a week.
4) Knock on doors 25-50 hours a week.
And that, folks, is pretty much it. Not exactly a breeding ground for intellectual development.