I always think of the perfect response long after these encounters.
  1. Naked old guy that is way too comfortable with his body wants to strike up a locker room conversation:
    "Look, I'm as big a fan of The Greatest Generation as the next guy, but how about you tell me about all the nahtzies you killed on D-Day after you are done toweling off your beanbag?"
  2. Gym Rat taking selfies in the locker room asks: "Can you take a picture of me flexing bro?"
    Subtly suggest poses that slowly tie a human pretzel. Then pocket the phone and GTFO.
  3. Unsolicited lifting advice from random strangers:
    "Yes, I have noticed how shitty my squat form is. But [terrible Samuel L. Jackson impression] I DON'T REMEMBER ASKING YOU A GODDAMN THING!"
  4. Folks who don't re-rack their weights:
    "Think Fast!" [tosses 25 lb plate at offender's crotch]
  5. Woman who aggressively invades my space while belting out Lauryn Hill's part of "If I Ruled The World" like she's auditioning for American Idol.
    Option 1: find the song in my playlist that is absolutely at the opposite end of the musical spectrum (probably Tool's Hooker With A Penis) and unself-consciously tone-deaf Rock Scream the chorus. Option 2: start doing crunches and wait for her closest approach to coincide with a break in the song and just really use the core muscles to unleash a protein powder inspired fart just as she starts to inhale.