Friends of mine and I often get into disputes — good-natured ones — about a concept that is expressed most commonly in Zen: that everything you need is right inside you, and that you don't need to seek outside yourself for truth but can find it right here in your own backyard.
It's a concept I've gone to the mat with constantly, because I've seen at least as much to refute it as I have to support it. Or maybe because it's easy to misinterpret as a kind of sullen, solipsistic screed. You don't need to learn anything from the outside world! Forget about all those nasty life lessons! Just dig down inside yourself and unearth the Riches Within! Usw.
I've deliberately caricatured this point of view as a way of demonstrating how easily it can slip into precisely this sort of goofy non-think. Goofy from the outside, maybe, but pretty seductive when you're wrapped up inside it and using it as a way to ward off anything that might pop your bubble.
After my own wrestling matches with this concept, this is what I was able to take back from it.
The lessons of the outside world are a given. You can take them or leave them, but they will always come on their own. What doesn't always come on its own is the spark from the inside — or, rather, it isn't always given the freedom to emerge spontaneously. To let that spring out of you requires a certain amount of putting things down and letting things go, so the signal can emerge without extraneous noise. (Sez Andrew Mckenzie: You're trying to become a radio receiver, rather than a radio transmitter.)
Remember John Cage's experiences in the anechoic chamber, wherein you could hear your own blood and nervous system? Proof to him there was no such thing as "complete silence", except as a concept in the abstract or as a direction to lean towards. The more you try to drop everything, the more you find already there in some form, waiting to bubble to the surface. I could make any number of analogies. I might well do that in time.
"The truth is inside you" isn't a substitute to the outside world — it's a complement to it. It's the oven in which the ingredients of your external experiences get baked. Then you have a nice loaf of garlic bread to go with your salad and your penne in vodka sauce.