P&G Salutes the Moms of the World in Olympics Ad
If this doesn't bring a little tear to your eye, you're not a parent. But that's OK. Because when you become one, you'll understand. There's really no way to explain until you, yourself, get there. Then, you'll understand.
Or you could watch this two minute P&G ad that touts the brand's sponsorship of the London 2012 Olympics and you can try to empathize.