> Empty your mind. Be formless, shapeless, like water. You put water into a cup; it becomes the cup. You put it into a teapot; it becomes the teapot. You put water into a bottle; it becomes the bottle. Now water can flow, or it can crash! Be water, my friend.
https://www.taoistic.com/taoteching-laotzu/taoteching-08.htm
There's also a really good and short Ted Talk on it: https://www.ted.com/talks/raymond_tang_be_humble_and_other_l...
At least he said that. Not sure if he was first to say that though.
Apparently when his martial arts teacher told him he was too forceful, to be more like water, and then banned him from practicing until he understood. Short story, he went on a boat ride, got angry, started punching the river, then he got that aha moment.
Bruce Lee was actually a really wise dude. I also highly recommend the podcast.