Quarter-Life Crisis

As I'm going through the motions of everyday life, I can't help but be unnerved by the number of things that I missed out on and that I am currently missing out on. I constantly change my mind and so I've gone from wanting to do graduate school full-time, to working abroad and traveling, to doing absolutely nothing.
I chose graduate school. Now, there are so many side projects that I am eager to pursue. I want to get certified for web development and graphic design. I want to do pottery and welding. I want to teach. I want to put everything aside and work for NGOs and charities. I want to move but then I won't have enough money to travel. I don't know if I'm being over-ambitious or just plain silly. I think it's leaning towards the latter.
I've been having these wavering thoughts ever since I graduated two years ago. I still don't frigging know what I want to accomplish with my life. I feel as if I should make a decision before my 20s are over so that I can spend the rest of my time going after it. I want to have enough time so that if I want to switch careers, I won't be doing it when I'm ready to retire. Is this what a quarter-life crisis is?

I just wikied the term and here are the characteristics:
. feeling "not good enough" because one can't find a job that is at one's academic/intellectual level
. frustration with relationships, the working world, and finding a suitable job or career
. confusion of identity
. insecurity regarding the near future
. insecurity concerning long-term plans, life goals
. insecurity regarding present accomplishments
. re-evaluation of close interpersonal relationships
. disappointment with one's job
. nostalgia for university, college, high school or elementary school life
. tendency to hold stronger opinions
. boredom with social interactions
. loss of closeness to high school and college friends
. financially-rooted stress (overwhelming college loans, unanticipatedly high cost of living, etc.)
. loneliness
. desire to have children
. a sense that everyone is, somehow, doing better than you

Wow. I want out of this rut.