Mushrooms on my Houseplant?!?

​Question:  I found a mushroom on my house plant this morning, and I’m really confused. I’m pretty sure that it grew overnight, how did it get there?

NICK: Mushrooms have something called spores; they're located underneath the mushroom. They are kind of like seeds. They are so tiny that sometimes you can't even see them. And when you're handling a mushroom, or if an insect gets into that mushroom, you could transfer that to a container quite easily. Now that container needs to be extremely moist in order for that spore to grow. So if you have just watered it, and then that spore got on there, well, I’ll tell you something, you got yourself a potential mushroom farm. It's really hard to kill something like this, starve the plant of water, and that might kill it off.