I'd say that my biggest failure was not growing a pair of balls, manning up, and choosing an area of study I was truly passionate in. I've finished my degree, but didn't pull the best results. Doesn't really mean much in way of career, as my career is pretty much on track. But in my own mind, I could have done a lot better had I chosen something not as bland and mundane as economics. I also had a Marketing major, which was more interesting, but it was still quite uninteresting bar a few units which were relevant, practical and interesting. The economics killed me. But I was never brave enough to perhaps transfer, or do something else.
My biggest failure would be maintaining a balance in my life. When your life is in some form of equilibrium, you function at your best, and at your highest potential. Your overall satisfaction with life rises drastically. That's my experience anyway. By balance I mean balancing time with your girlfriend / boyfriend, family, friends, work, and most importantly, for yourself. Time alone is important, and if you don't get enough of it, you feel sluggish. At the moment I'm struggling a lot to maintain a balance, but am failing, and it's affecting my life in a very negative way. But I'm aware of this, so I can overcome it.
I generally fail at being satisfied and content. I think it may be a generational thing (as in, generation Y), as I constantly feel restless, dissatisfied, and always yearning for something else.. something more. I am very appreciative for what I have, but for some reason, I can't seem to escape this incessant feeling of dissatisfaction.. always wanting something else. Thinking I'll only be happy if I do this, or have that (not just material things..). Can anyone relate? I find that to be a big failure of mine.