I've also got a young child that started nursery a few months ago. She's hardly ever without running candles and I seem to catch far more colds now than I can ever remember even though I'm fitter now thanks to cycling. Having said that, I do seem to be able to shake them off pretty easily.
After a while you might become resistant to it. When I started working in a special school (think runny noses, spit, crappy nappies, and kids coughing in your face) I constantly felt a bit off for six months, but then it stopped getting to me. Three years on I get a cold maybe once a year.