I went camping as a scout once. Okay, more than once, but I am only thinking of the one time right now. We were in a little valley and we pitched tents on a slope. It wasn't steep; at least while we were walking around on it, but at night everything and everyone slid to the bottom. I awoke numerous times to Jon cursing the name, "Newton" for inventing troublesome gravity.
During this same trip, Jon also came up with the malapropism (but can you call it a malapropism if it's done on purpose?), knifes to substitute for nice. As in, "We got a knifes warm fire going!" I really like it, because it's so subtle, so I adopted it into my vocabulary.
Since then, me and my roommate Jared and I have come up with several other on-purpose substitute words using real words (we really like messing with English majors): Muffin meaning nothing, as in, "I tried to roll a horse, but I got muffin." And meow instead of now: "Stop talking like that right meow!"