For a month I've been exploring what 'I want' is and the day before yesterday I felt that I reached a milestone. [Let us define the notions!]
In most cases 'I want to do X' for me means not future simple or continuous but present perfect continuous.
I'm not talking about cases like 'I want to have a fruit salad for tomorrow's breakfast' or 'I want to wear this particular suit at tomorrow's meeting'. I'm talking about phrases with no particular time limit, like: - I want to take up dancing; - I want to study French or any other foreign language; - I want to learn how to draw; - I want to lose weight; - I want to go to India - I want to be a designer etc.
I want to say here that I strongly believe that if a person says that he or she wants to draw but does not draw - he does not want it. If a senior at school declares that (s)he wants to be a designer but hasn't ever drawn a sketch of anything, any label or a piece of clothes -anything - I don't believe these words. I don't think that this person wants to be a designer.
As for me. When at 13 I decided that I wanted to be a writer, I had had already hundreds of pages (unfinished novel, short stories, verse, drama scripts) written. When at 14 I decided that I wanted to be a musician, I had already been playing the piano since 7 and the guitar - since 12. When at 14 I decided that I wanted to study Japanese, my mother found a teacher for me in several days. My first and dearest sensei. When at 19 I decided that I wanted to take yoga classes I had been doing yoga (almost every day) for 4 years. When at 21 I decided that I wanted to enter the university again, I had been studying Japanese for already 7 years. When at 22 I decided that I wanted to take up running I went for a run if not the next morning then anyway in 72 hours. When at 22 I decided that I wanted to publish "Love letters", I had had the first volume already translated. When at 24, this winter, I decided that I wanted to take individual lessons of French, I had been studying French by myself and several months I had been attending courses - for a year and a half. When at 24, acutally, several days ago, I decided that I wanted to take contact improvisation classes, I had already been practicing a kind of contact improvisation for 5 years, with a great master of this particular form.
And I'm still there. I still write a lot (you see it here), I still play the guitar (though I had a break for two years), I study Japanese, I do yoga almost every day, I'm not sure about running because I'm thinking about a balance between running and CI - or I'm quitting running as I'm not doing it - not sure yet, but I still study French and I dance CI.
I believe that if you want to do something you must already be doing this for a while. Or start doing this in, say, 72 hours. If you want to dance, you needn't take classes. You can find a place, switch on your favourite music and dance. If you feel uncomfortable not knowing some basic moves - open youtube for god's sake! and search for "[name of the dance you want to try] basic steps". If you want to study foreign language, do it now. Download a textbook - there are plenty of them on rutracker.org - and try learning. Unless you try you can't say that you want to do it. If you want just to try - try in 72 hours. Okaaaay, not everything can be given a try in 72 hours. Two weeks. Tops. If you want to do something which takes a lot of money or other resources, ask yourself: what am I doing everyday to make this real? Make a habit you love from 'I want'. Read Leo Babauta's blog is you don't know how to form habits.
Just don't lose your motivation. Don't lose your "I want".
In sum: "I want" is a decision. I can say that I want to do X if I have already been doing this for a while. The less gap is between "I want" and "I do" - the better.