I like the idea of making things more than just acquiring knowledge. There's just too much information out there for any one person to know; but, I do think it's possible to be good at creating various things.
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So, my questions for you are:
- What subjects would you try to learn?
- How would you go about learning these various subjects?
In my teens I moved to argentina and got a job there which forced me to learn spanish well ( still stuck with el accento porteno ). In my opinion there's nothing better for opening up your mind like moving to another country, experiencing other world views, literatures, culture, etc.
Make a choice to learn something and stick with it until you master it (but make sure its something you enjoy). The toughest for me was sticking with Mathematics, because apart from trig, relational algebra, and discreet maths I hardly ever have a chance to apply the rest. So I just set apart some time daily and worked from the bottom up, its constantly more fascinating and I really miss it when I can't spend my daily time with my mathbook (currently 'pattern calculus' by barry jay - highly recommend.
I'd say delve into diverse subjects but don't try to be a master of all. Its one thing to know who decartes was, how he arrived at cogito ergo sum, and yea the cartesian plane, but you'll never be able to know it all and a lot of its completely useless. For me, after a year long period where I read into philosophy in depth I pretty much decided the whole field was pointless (for me), and decided to concentrate on disciplines that were more applicable and enjoyable for me such as physics and political history.
Lastly, to quickly answer your question about which subjects to learn I'd say the following a good for getting an overall understanding (and will keep you more than busy for quite a while :)
1. The world of the abstract - Math
2. Understanding the universe and our relationship to it - Physics
3. Life and living organisms - Biology and evolutionary theory (Dawkins, Dennett )
4. Humans and our cultures - History in tandem with at least near native fluency in one foreign language (and accompaning culture, literature, films)
5. The Mind and brain how we think and are - Cognitive Science - Gödel, Escher, Bach (GEB)
Best of luck its a very fun path learning things and then applying what you've learned!
Also unless you have a trust fund you should be spending a good part of the next nine years figuring out how you are going to support yourself for the following fifty.
But, more to answer your question: I'd choose a maximum of 3 (and even that is pushing it), then immerse yourself deeply in them. If you're wanting to make things, then practice it as much as you can, regardless of the quality. It took me many years to not feel ashamed of my guitar playing, but it has finally started to take hold.
Art demands a lot from you emotionally, but it's not any fun otherwise. :)
Try to take classes, but just launch full speed into new goals. For example, to learn photography I bought a nice camera and darkroom and $1000 worth of film. To learn car repair, I bought a cheap Italian convertible and rebuilt it as a member of an online community (engine modifications, transmission swap, etc.)
You can speed up learning by setting daily structure, ex: Pick 7 things to work on each week (based on your weaknesses) and devote one per day of the week. Perhaps set month goals such as reading a book per month, competing in an event, etc. Set year goals, etc.
World study (travel, language study, history) Physique (martial art, endurance sport, yoga) Music (history, instrument, theory, singing, etc.) Art (photography, architecture, graphic design, painting, drawing, creativity, etc.) Mechanical (get a cool old car and learn to rebuild it, 4 wheeling, convertible, welding) Construction (improve a house, wood working, furniture, etc.) Acting (role in a play, improv, standup jokes) Psychology/Religion (explore meditation, church service, personal development.) Mathematics (history, chess, classic texts)
Business? Computer Engineering?
1. Stop watching broadcast/cable TV. Only watch a few really good shows via iTunes so you don't waste time on commercials.
2. Listen to non-fiction audiobooks when getting ready in the morning or driving/commuting. You can gain a broad range of knowledge with what is typically down time. The knowledge is valuable on its own, but really becomes useful when you start creating your own material.
3. Cut your news reading down to a few broad weekly/monthly publications like The Atlantic and The Economist.
4. Watch Charlie Rose. You would be amazed at the breadth of guests he has on.
5. When you meet others, ask them about what they do and really talk to them about it. Small talk is a waste of time. Ask detailed questions about different fields and you will find you learn quite a bit in the process.
6. Always ask "Why?" when you encounter new concepts.
Understanding how others try to steer your thinking and actions is as important to a renaissance man as the ability to sketch the valves of the heart or conceive a flying machine inspired by nature.
Off the top of my head:
a. Live where you can get by mostly walking or riding a bike. That will help with fitness. b. Take some classes. If you already know a musical instrument or two, I suppose you can learn another easily. From a given level of mathematical maturity, you can learn more math on your own. But foreign languages, drawing, and painting seem like skills you can use some help with. Community colleges, university extension programs, organizations such as the Academie Francaise and the Goethe Institute offer things that can help you. c. On your own, you can read plenty of history. d. Philosophy is worth reading, but requires some context.
Good luck.
Note that the first thing that came to my mind when I read your post was: "To be a true Renaissance man, you need to have been dead for 400 years". I won't write it here :)
The reason I suggest this is without clear goals and a practical application for those goals, you may not get the outcome you desire.
Simply find what you love doing.
Things in life change and 10 years from now you'll have different interests. Cultivate the things your interested in now and don't over stress yourself with having to learn all those disciplines - things will come with time.