Off topic off day question

When I was a kid, I believed everything anyone told me.

One story that sticks in my mind took place when I was about ten.  I don't remember how old I was, but whenever I can't remember for sure, I just assume I was ten.

Anyway, there was a place in Fort Worth called GDRA (General Dynamics Recreation Area).  I'm not sure if it still exists, but it had a bunch of soccer fields, a gym, and a big swimming pool with 5 and 10 meter platforms along with the regular diving boards.

The 5 meter was usually open, but the 10 meter was usually closed off.  Another kid told me one day that the 10 meter was closed off because someone did a bellyflop off the 10 meter, and they hit the water and busted open and their guts came out into the water and they died.  And so the pool had to be closed, and they had to bring in a shark to put into the pool to eat all the guts to clean out the pool before it could re-open.

And I believed him, because I was an idiot.

Anyway...this got me wondering...

What was the most ridiculous story that someone told you as a kid that you, in your child-like naivete, assumed was true, and look back on now and think, "How could I have been so dumb?"