Views From the Other Side

I'm waiting, yea it's me your old pal. Remember last summer when I surprised you and broke off your fly! That was fun almost had me, yea, I'm the one everyone talks about, I get bigger ever time one of you guys has a brief encounter. Sometimes you say I was that old brown, next time I am a rainbow, growing larger in my legend, keep guessing. You'll never get me, I'm the one that got away! Keep trying anyway, it's been fun!
See ya soon, name the river, I'll swim there! You'll never catch me!