You can't surf around fitness web sites or forums without running into the Internet tough guy who exaggerates his fitness capabilities or outright lies about them. It's been going on for God-only-knows how long in every form of media and word of mouth alike. It sells stuff, it makes heroes out of fools, and it strokes highly sensitive egos the world over. If you look around any fitness forum, I'm sure that you can find someone inflating their handstand push-up rep count, passing off someone else's intensely-muscled body as their own, or lying about the length of the rope that they're climbing in their latest Youtube video.
Outside of the need or want to sell something, I don't get why people lie about their physical capabilities. First of all, one good look at the liar-in-question and you can tell if they can really do what they're claiming. It's almost pointless trying to sell the notion that you can do 25 handstand push-ups (yes, I heard this before) if you're a semi-solid (or semi-flabby)230 lbs. It's also a little foolhardy to think that anyone's going to believe that you're 5'10" and 250+ lbs of solid, drug-free muscle. Most of us who train know better.
Think about it this way: the average, American man can only do 4 pull-ups. 10 pull-ups may not be impressive to some but it's quite a bit above what most can do. So, trying to say that you can do well-over 20 is a little bit of overkill if you're trying to sound like you're in good shape.
Furthermore, why do such people care what others think of them? Walking through life, worrying about how others see your athletic performance shows some obviously high levels of insecurity. For crying out loud, grow a thicker skin and screw what others think of you. If they're going to deride your efforts, then you shouldn't be listening to them in the first place. Don't drop yourself down to their level by lying through your damn teeth!
That's one thing that I swear I'll never do. I'll never lie, or exaggerate, what I'm capable of doing. If I can, I'll admit to it. If I can't, I'll say so. I'll come right out and admit that I have a very difficult time doing Pistols. Before I threw my back out, I was getting 10 on each leg. Now that I'm much better and able to do them without an issue, I struggle to do 5 consistently. I can't do a lot of the more gymnastic-based BW exercises, such as flags and planches either. I know I'm definitely above-average in general physical fitness but I have no illusions about being at an elite level. So, I won't sit before this keyboard and make myself out to be something that I'm not. I'll just train my ass off to get there.
Frankly, that's what most of these shaved-apes and jackasses who spend their time dreaming up their fanciful feats of strength ought to do. They need to shove away from the keyboard and do some real, honest, and hard training. Who knows, if they actually focused their efforts on their workout rather than on their next line of bullshit, they wouldn't have anything to lie about anymore.