It's really mostly logic when I think about it. My son is just 2 months shy of turning 3 and just hates when something goes wrong with his body. Especially his nose. Why should it run at certain times? Well, low and behold he got himself a cold and his nose started running. While I was putting him to sleep last night, laying beside him because bedtime was earlier than normal, he all of a sudden sat up saying that something had crawled into his nose. And the freak out started. Having him put his head back, I turned on the flashlight of my phone and took a look. No boogies, I told him. Just a pea. From dinner. Shoved up there.
Now, after I got this out, I thought to myself, what a logical idea. Something is running, take whatever you can to stop it. Makes sense to me.