Old Fish and Young Fish (Habits)
There are these two young fish swimming along and they happen to meet an older fish swimming the other way, who nods at them and says, "Morning, boys. How's the water?" And the two fish swim on for a bit, and then eventually one of them looks over at the other and goes, "What the hell is water?"
The water is our habits. It's the unthinking choices and invisible decisions that surround us every day. Only by stopping to notice the water, can it even become visible again.