I Guess He Should Hope for a Full Moon?

We were watching a weight-loss show and Andrew asked how someone would get so heavy (the guy was close to 500 pounds).
I told him that as long as he exercised he probably wouldn't need to worry about it.
He replied, "I do like to ride my bike and that's exercise. But I don't like to ride it when it's sunny. That hurts my eyes. And I don't like to ride when it's cloudy. I'm afraid it will rain."