That's a great sentence. Could possibly even be boiled down to "you need a problem," since trying to solve problems is the way to develop skills.

"No battle plan survives contact with the enemy" -- Helmuth von Moltke the Elder

"In preparing for battle I have always found that plans are useless, but planning is indispensable." - Dwight D. Eisenhower

...but, planning in place of action is planning on failure.

I'd heard that as Winston Churchill.

http://en.wikiquote.org/wiki/Churchill

A member of the National Academy of Sciences of my acquaintance once said that life was too chaotic to plan beyond six months.

Nice article, except the Columbus reference.

"I will solve XYZ problem" is a plan.

More of an intention.

I somewhat agree -- my first reaction was to append "and then a plan" to the end of the sentence.

But I think the most accurate take on the subject is this:

"I have always found plans to be worthless, but planning indispensable." --Dwight D. Eisenhower

An important distinction I think.