Pick an "awesome" super power, then figure out all the reasons why it would be absolutely terrible to have.
If you think about it, I suspect every super power you can come up with would be dangerous, impractical and impossible (for more reasons than the obvious). You might even be surprised by some of the ways it simply wouldn't work. The obvious reasons most powers couldn't exist is that they defy the laws of the conservation of matter and energy (producing something from nothing). But the other possible consequences of those powers might be more subtle.
Here are a few that come to mind:
- Super Strength - You'd be scrawny as hell. Muscle comes from physical exertion. If lifting a car is easy for you, where's that exertion going to come from? Bench pressing trains? Lifting mountains?
- Super Speed - Depending on your speed, any of the following might become an issue for you: 1) black outs from loss of blood flow to the brain, 2) your skin being torn from your body, 3) your skin melting by super heated air, 4) a nuclear explosion by the rapid compression of atoms (assuming you're going near light speeds).
- Stopping Time - You'd be blind. Sight comes from the absorption of photons after they've been reflected off of objects. No moving photons means no way to see. Oh right, and you'd suffocate (no oxygen flowing into your lungs). That might be bad too.
- Energy Projection - Congratulations: you're a battery now. You can create energy out of nothing, why have you fight crime when we can stick you inside a chamber where you can use your power to crank an engine and power a city nearly indefinitely and practically for free?
What other reasons for these and other powers would make them shit to have?
[Edit] I'm being criticized for not auto-accepting comic book explanations for super powers or for not automatically assuming the super human's body would be suitable for their powers (like a speedster automatically having super endurance and strength, etc). I'll provide context for my motivation in creating this thread:
My point of making this thread was in the vain "What super power(s) would you want?" but taking it a step further "Are you really sure you'd want that?"