"Use only that which works" is obvious enough to be unhelpful, but "take it from any place you can find it" was pretty novel in the context in which he proposed it, and still is to a lot of people in a lot of domains.

The existence of the Traditional branch of Jeet Kune Do (as opposed to the Concepts branch,) which exclusively teaches the martial art as Bruce Lee practiced it at the time of his death, is testament to the strength of humans' tendency to behave counter to this advice.