These are some banal wisdoms I've come across pondering the strange and wondrous metamorphosis of my l33t sk1llz in playing the piano and other keyboards. I found they also apply to my learning of programming languages and to the acquisition of knowledge and capabilities in almost any other respect. Of course, your mileage may vary; I'm not claiming this holds true for everyone.
1. Get started.
Making headway into the waters of something you have, so far, completely ignored isn't exactly easy. In our family, we always took it for granted that I would take up playing the piano, and so it came; we also took it for granted that only angsty teenagers without any discipline or guts give up music in their puberty; sensible children such as me would just keep going.
This stance is debatable, but it ultimately helped me to make it through years of good and bad times with my friend, the piano without giving up so I could acquire a decent foundation of technical knowledge. I suppose that with everything that has a steep learning curve, you need something that just forces you to go on with it for some time at first.
This first kick can of course be delivered by a friend, too. Or you can simply invest a great deal of money in musical equipment, O'Reilly books, Asian foodstuffs, whatever matériel is related to what you are trying to learn, so you will feel obliged to do something with all that expensive stuff. In the piano case, you could e.g. take up lessons and pay your instructor in advance for two years.
2. Be aware of your mediocrity.
Know how much you know. (Not much.) Know how much you don't know. (Very much.) This is important. With a strong sense of how mediocre you really are, you won't become delusional about e.g. going from zero to boogie woogie pro in less than a year. Awareness of your mediocrity also means respecting yourself, though -- it means knowing about your (limited) skills and what you can do with them.
To me, Germany's system of musical contests for youngsters, Jugend musiziert, was essential in this respect. The contests showed me how mediocre I was, and strangely, this did not make me angry. It brought peace to me and gave me some kind of inner balance. I, like totally, zenned out.
3. Be bold if appropriate.
Be bold especially about doing things you've never done before. Undertake strange new things, but only if you've got a good reason, otherwise it'll look arrogant. For example, I took up conducting a small choir. Well, it's not really conducting since I never did that before -- I'm still learning. I only do it because we found no one else to do it, I would have looked foolish volunteering for something I did not really know. Well, so I'm leading this small gang of buddies trying to make sense of, say, Queen's Somebody to Love, and in doing so, I learned a zillion of things, such as singing falsetto (to demonstrate stuff, since I'm a low bass), playing four-staff choral scores on the piano or singing and playing at the same time.
I was similarly bold when I first got the chance to play continuo harpsichord with an orchestra, when I became first became a keyboarder in a rock band, and when I was first offered to play piano in a jazz combo. Every time I ended up learning a lot.
4. Make use of your knowledge for its own sake.
If you know how to do something, on every occasion where you can make use of it, do it. I've played the piano on countless boring evenings, accompanying choirs, singers or instrumentalists, playing in a quartet, and never getting paid all that much. However it gave a sense of purpose to me as a musician.
5. Procrastinate creatively.
When you're sick and tired with doing one thing, do something else, but related. Actually, I'm noding this just to procrastinate.
Cleverly putting off something (like wrestling with a Bach fugue or a Czerny etude) by doing something else (like practising to rock like a beast) has done wonders to my non-classical piano skills. Similarly, building the most recent CVS versions of GNOME software packages just as an excuse for not having to work on learning C and GTK+ has taught me a lot about autoconf, automake and fixing build glitches in source trees.
6. Don't be too serious.
This applies to everything. If you're working on serious stuff such as II-V-I progressions or The Great American Compiler, treat yourself and write yet another Tetris clone, practice a cheesy rendition of 1980F or record an a cappella version of Paranoid (caveat: this takes at least six overdubs if you do it alone).
I hope you enjoyed this enormous heap of self-righteous platitudes -- there's more to come!