Yeah, I'd be all for the whole immune-system-build up -- snotty noses aren't *that* bad, except that her colds had a funny way of turning into horrible middle-of-the-night wheezing attacks...
After four emergency room visits, we told the pediatrician this was getting ridiculous and he got us some stuff so we could do home care, and we've avoided the hospital since then... BUT since I pulled her out of day care (for unrelated reasons), we haven't had to treat her at all. I'm not looking forward to revisiting all that. It's no fun not to be able to breathe... But maybe (maybe?) her lungs are a little bit stronger. I similar issues when I was a kid, and I outgrew them... but at age 7, not 4.
