I’m going with penmanship. You?
Épée.
Politics is (what I hope to be) the serious answer.
Valete,
Vox Imperatoris
Try harder
It is glurge, but it is good glurge, and personally inspiring to me: the Desiderata poem.
“If you compare yourself with others, you may become vain or bitter; for always there will be greater and lesser persons than yourself. Enjoy your achievements as well as your plans. Keep interested in your own career, however humble; it is a real possession in the changing fortunes of time.”
Just run the fucking marathon. Not everyone can do it, it doesn’t matter how well you did it, but when you did it you will have done something only a few people can do. If not a marathon something else.
I’ve been feeling rather mediocre lately myself. 
Of course my standards are really high and I’m too lazy to meet them. I am saved/cursed all at once by a massive ego and the conviction that I’m a genius. However I have little to show for it. Just do something and complete it. Tighten every nut, every bolt.
Definitely drive can be found through exercise. It might very well be that you are not getting enough energy around your body and feel lethargic. Also discipline is achieved by just exercising it.
Just do it.
Also remember that one person’s mediocrity is another persons accolade. Just because you don’t necessarily consider what you’ve achieved that great doesn’t mean other people wouldn’t (you don’t just have to compare yourself to a child living on a rubbish tip in India to do that either).
Anyway, as sovtawen said, what are you hoping to get out achieving things? If it’s recognition from others it will always feel hollow and you will doubt it unless you really feel for yourself that what you did was worthwhile.
That is further proof that everything is relative. I have known rural farmers here who would slit their grandmother’s throat if it meant having a life like the OP’s. Or like those Wal-Mart employees, for that matter. And yet, I can relate to the OP’s feelings of mediocrity. I vividly recall taking my bright, shiny new bachelor’s-degree diploma to Manpower and being sent to sort cardboard boxes at Frito-Lay for a few months. That certainly did not make me feel like I was in any sort of elite.
My advice to the OP (besides the skydiving course): Things change. Nothing stays the same. If you don’t like your personal environment, then change your personal environment. It’s going to change anyway, so you may as well change it to suit yourself before it gets changed for you.
Go to Comic-Con. Every time we go, we are the skinniest, handsomest, cleanest couple in the place.
Mediocre only shows up when you start to compare yourself with others.
Can you enjoy what you have in your life? Does your presence on Earth come out even or give the rest of us a net positive? Do you have a connection with your fellow human beings? Is there anyone or anything that is glad to see you come and sorry to see you go?
Just think, there’s probably someone out there wishing they had it as together as you do.
Could you support yourself as a subsistence farmer? How would you do if the only water you had to drink was collected rainfall? How would you deal if you didn’t have electricity?
Frankly, I find these skills more impressive than what you’ve accomplished, and you seem to be automatically discounting the people who have them because they haven’t run half marathons or held a steady job.
The thing is, scratching out a meager living from the scorched earth, while it may be quite an accomplishment over my own meager skills, is not as likely to advance the lot of humankind as a whole as, say, some other people’s highly trained expertise.
Well, that’s true. I didn’t realize that was the scale by which we were measuring. Okay, then.
But then, if I were stranded in the middle of nowhere, I’d definitely go with the dirt farmer and sacrifice the plastic surgeon.
Limit yourself to one pity party a week. Self-pity totally kills your oomph.
Drink
You’re in good company, because 99.9999999% of humanity will never do anything remotely remarkable, great, or otherwise noteworthy. They will live, they’ll die, and a few generations later they’ll be forgotten. That’s life; it’s ultimately meaningless anyway.
If you do just want to spice it up personally, just drink some tequila and do whatever seems like a good idea. It’ll give you some stuff to reflect on in the morning.
I think a lot of us have to come to terms with our mediocrity. See, we might be a little brighter than average, and a little more self-aware, so we realize that there are things out there beyond “People” magazine and reality tv, but we aren’t quite bright enough/talented enough/driven enough to go out and get them. I think the only thing left is acceptance - you are what you are. If running a marathon is a realistic goal for you, go for it. If not, figure something else out and go for it. Just don’t expect to be the next world leader, because none of us is destined for those lofty heights.
Climb up the side of a skyscraper like that french guy. Nothing mediocre about a little airtime on tv and a mugshot
Hey now, that’s rather harsh. I personally think my goal of PM of Lower Slobovia isn’t so unattainable.
Strangely enough, I recently had a sort of existential crisis after watching the brilliant documentary Man on Wire recently. For the unaware, it chronicles the efforts of Philippe Petit to tightrope-walk large structures, culminating in the grand finale, the steel Everest of the World Trade Center, which he successfully (and luckily) conquered in the 70s. While watching this film, it dawned on me that this guy, who spoke about his dreams so passionately and poetically, had a towering, almost insurmountable dream but still managed to realise it. The tight-rope walk, the media frenzy, the sense of achievement, all the antithesis of mediocrity.
I came out of the movie theatre realising that I had no such goals. I had no wider vision, no Twin Towers to conquer. I was doomed to mediocrity.