In a person there are things that were taught by others, and things that grew out of himself.
What others teach are the rules: queueing, being on time, leaving room in what you say. What grows out of yourself are habits: a cup of hot water in the morning, shoes off at the door, soup with a meal, red paper put up at Chinese New Year, chopsticks that must never stand upright in the rice. Rules you sometimes forget. Habits you cannot forget — because they are not something you remember, they are something you grew into.
The word su（俗 — the way a place lives） — custom — means the second kind.
In chapter 80 of the Daodejing there is the line le qi su（乐其俗 — to take joy in their own customs）. In front of it stand gan qi shi（甘其食 — to savour their own food）, mei qi fu（美其服 — to wear their own clothes well）, an qi ju（安其居 — a dwelling they can rest in）. Read together, the four are not about wealth but about a person being content with his own days: food that tastes good, clothes that look decent, a dwelling he is at rest in, and a life lived by his own customs — and taking pleasure in it. (Our own renderings again, not a quoted translation.)
Note those last words: taking pleasure in it.
Su（俗 — the way a place lives） does not mean "low." Some people hear su（俗 — the way a place lives） and think "vulgar." But it is the su（俗 — the way a place lives） of fengsu（风俗 — the customs of a place） — the customs of a place, one way a people has of getting through life. It has no argument to make and needs none: here in China, whether soup comes before or after the meal differs from place to place. Nobody can talk anybody else out of it, and yet each side is sure the other ate that meal wrong. That is not prejudice. It is the body knowing what "right" is before the reasoning gets there.
Habit is a person's nest.
Out in the world you have to hold yourself a certain way. You speak according to the occasion, you work by other people's rules, you show up looking the way you are expected to look. That is not hypocrisy; it is what the days of a grown-up require. But a person cannot be out in the world every hour of the day. There has to be one place where you do not have to hold yourself that way.
That place is usually the place where your habits decide.
Taking your shoes off at the door is a very small thing. It solves no problem; nobody pays you a cent more for it. But the moment it happens, you know: I am home. The same with the cup of hot water in the morning, the chopsticks laid straight, the "I'm off" said on the way out. Not one of those things is necessary, and yet together they are what "my life" looks like.
So le qi su（乐其俗 — to take joy in their own customs） does not mean "tolerating other people's habits." It means: a person has the right to be at ease in his own.
You do not first have to turn yourself into someone else before you count as "integrated," or "advanced," or "enlightened." You may keep your own tastes, your own festivals, the way you visit relatives and friends, the way you speak. And so may everyone else.
That people differ is not itself a problem. The problem starts when someone thinks "my way is the default, yours is the special case."
Habits do not need to be changed. Only one thing does: stop treating another person's habits as something that needs correcting.
The three words le qi su（乐其俗 — to take joy in their own customs） — we keep them as a saying.
They do not say what we do. They say what we hold to: that a person living his own way is not a flaw, it is simply how things should be.
A life, in the end, is just this: inside your own habits, slowly and steadily, turning yourself into a person who can say "this is how I am."