Experience, then books and challenge tests.
I know you can't do it that way, but perhaps you can "sorta" do it that way. The advantage you'll have with the academy is THE LAB. In addition to the excercises, think of a scenario and try to implement it. As you need to find out the "how," do some knowledgebase scans at cisco.com, look in the books, and find the answer (then implement).
The problem I have with most training classes is that they tell you, step-by-step, and give you the exact thing to do.... you do it, then forget it (unless you actually use it with some frequency). By coming up with your own scenario and having to research it, the information "sticks" a little better .. plus, you'd be surprised how many other "answers" you'll come across while looking for something else.
I didn't "grow up" in a Cisco environment, but the principles were there from exposure in the field. I usually found a challenge test (Bosun is usually good, especially for Cisco R&S), find out how lame I am at the topic, then hit the books and equipment, then follow with some more challenge tests to evaluate my progress.
I still don't have the majority of less-used Cisco R&S commands firmly committed to memory, but I know where to look to get 'em fast if I need 'em (the "Field Guides" from Cisco press has been very helpful). I have my own rack to play with (rack.scottmac.net), and nearly all of the Cisco press books (and others) ... you can't stop learning ... too much stuff changing too often. I've been doing this stuff for over twenty years now; when someone comes out with new technology, it makes my head hurt trying to come up to speed ... old age sucks.
Anyway, get creative and get some hands-on ... kick it with some research and reading, and check your skills occasionally to see if you're progressing.
That's my .02
Good Luck
Scott