“If you think you're too small to be effective, you've never been in the dark with a mosquito”
“If you think you are too small to be effective, you have never been in the dark with a mosquito!”
“If you think you're too small to make a difference, you've never been to bed with a mosquito.”
“If you think you're too small to make a difference, you've obviously never been in bed with a mosquito.”
“If you think you are too small to make a difference, you have never been in a dark room with a mosquito”
“Anyone who thinks he's too small to make a difference has never been bit by a mosquito”