Hello hello,
I have always hated treating "intelligence", and its parent "greatness", as sensible, applicable, or relevant terms, but rather as a discrimination with little substance. Yet, here I am, basking in this supposedly senseless concept like a MENSA member, following my nose to find what I may.

My story...
I learned to read around the age 1 mark, how nobody knows... the leading theory is from subtitles. Obviously I could speak quite well before then.
I read every word I saw, and looked for more. Dictionaries and newspapers originally, eventually I was given books on general science and became obsessed with astronomy for many years.
By age 4 I had memorised the multiplication and division tables with an almost complete understanding of elementary arithmetic, loved science also, could write, and most oddly had memorised over 60 hours of movie dialogue. I can also spell every word I know, and always have been able to... there is an undeniable link between the word and the letters it is composed of, a natural conceptual link that memorisation techniques are designed to exploit.
I did not actively associate with anybody until high school. I remember very often wandering school grounds alone and lost in some abstract world (like a virtual world from a video game), during class time originally. To illustrate the intensity of this, even up to ages 10-12 I would circle poles in a certain manner, walk back and forth along seats, only step on certain parts of the ground if there was a pattern, balance on logs, climb trees, play games within the house involving not touching the ground etc... and when I attempt to write creatively it is nothing but a sea of adjectives; nothing physical within the story occurs unless I am writing for hours; purely descriptive.
On my preparatory examination I was tested as 6 years ahead of average in math, and 3 years ahead in english. I was not accelerated because my motor skills were relatively poor and because it is very difficult, I imagine, to make allowances for such cases. I was tested again 6 years later and found to be 5 years ahead of that average, in both math and english, though I had learned almost nothing new.
I have been to 11 schools in my life and home-schooled on three separate occasions. Most of the time this was because we moved house, while most of the remainder was due to some form of detachment on my part.
I was not exposed to the internet until I was 11, and I think that was a great disservice on my part.
I was accelerated from year 3 to year 8, but alas was moved.
When I reached about 12 and a half, my entire world-view changed entirely. Before then my record was almost perfect. Since then my record is probably below average. The more I came to understand about the world the less I could tolerate the institution. I was driven to medical depression multiple times over the subsequent years due to pure anger. I saw society for what it is, you could say.
I fought with my family to be taken out of school for many years. The home-school occasions were many more years behind me and I remembered them as akin to my first four years of life. I was denied on all fronts, because my social skills would be damaged, they said. The problems escalated. I taught myself to associate and then renounced all I had learned. At the worst, I could not sit through an assembly without a breakdown, ignored all of my lessons and worked independently from the syllabus, was angered to the point of trembling by a certain word or phrase used in a certain way well over a hundred times per day, and could not complete much of the coursework either for what it stood for or, more often, its philosophical questionability. My main defense mechanism was pretending that other minds did not exist (very possible by the way). While most would find that terrifying, in it I found salvation, to be the only person alive.
Finally I was diagnosed with Asperger Syndrome and granted freedom with a medical exemption. (: The home-school system here is not self-paced, a heavy blow, but if I spend my time well it needn't matter so much.
I am Australian and 15.

What I would like...
I have been rather obsessed with philosophy for the last two years, spending hours per day on various forums. That is partly why I was driven here... people that do not refuse to believe I am 15 tell me I am wasting myself...
They tell me I need a direction, and of course I have always felt it. I think that anybody I know of who may direct me more effectively than I may myself is far too occupied. I still have the determination necessary to devote my 16 hours per day to some cause.
If you say "then choose a cause, something you are passionate about, simple", then I give you the answer "Enlightenment". And as the saying goes, you only know what you know. The best I can do is follow my nose, which is what I am doing, but certain situations will give me more than others. Certain people will give me far more than nothing.
I don't need information. The internet has all I could ever dream of. I need engagement. Constant discussion and mutual reasoning and conclusion, for virtually everything. That is my sole, half-formed motive.