"Waterfalls"

Don't go chasing waterfalls
Please stick to the rivers
And the lakes that you're used to

Chuck Klosterman does my work for me in his recent book Eating the Dinosaur:

"At the time [1999], TLC was advising me not to hang around with scrubs. This was kind of like their advice from 1994 about not chasing waterfalls. I never got that. Why not chase waterfalls? They're so easy to chase. It would have been far more sensible if deceased arsonist Lisa Left Eye had told me not to chase something dangerous, like wildebeests. 'Don't go chasing wildebeests.'"

"Don't go chasing wildebeests" scans nicely, but I'd be tempted to add "especially not into unfamiliar lakes and rivers they cross in large numbers, as you might get eaten by hungry crocodiles" before "Please stick to the rivers and the lakes that you're used to."