My wife was a severely germ-sheltered child like that. She has overcome it, and she does not get sick any more than I, a pretty grimy/dirty/often-filthy farm kid, do.

The hardest thing about that upbringing for her is that her instincts toward our children are very much geared toward avoiding germs at all costs. Because that was how she was raised, that's the only way she really knows how to raise our kids. Fortunately, I'm there to get them really, really dirty.