I agree, but at the same time, you only learn by doing. This is true, but I think in the original poster's case it could be much more easily and reliably be ac

I agree, but at the same time, you only learn by doing. This is true, but I think in the original poster's case it could be much more easily and reliably be accomplished by continually giving him problems that are within (or more ideally, just outside) his circle of competence, rather than a problem like "predict stock prices" which isn't in any human being's circle of competence. Moreover, with the latter problem, he'll get virtually no feedback as to whether his answer was correct, because a correct answer for "use statistics to predict stock prices" doesn't exist. Odds are that if he follows that path he'll quit before making any progress, or at the least he won't be able to close the feedback loop that is so vital to gaining expertise. I think that if he's starting from ground zero and wanting to learn statistics, he'd be much better served by sitting down with The Cartoon Guide to Statistics and a deck of cards and set of dice first. He can work his way up to conquering the stock market :) Don't tell Google that it's slogan ("Organize the world's information") is biting off more than it could chew. I think that's apples and oranges - he's trying to learn statistics, not trying to convince potential clients or investors that he's already an expert. I don't think it would be harmful at all for him to have a lofty, far-out goal like "predict stock prices" to aim toward, but I do think that if he starts out trying to learn statistics by typing "statistical stock prediction methods" into Google, he will burn out rather quickly. Pagefaulting in knowledge when you need it is probably optimal for something where you just want to make sure your knowledge is passable, but if he wants to truly know his domain, he's gotta get out the marbles and urns. :)