In the Book of Rites, in the Great Learning, there is a line that records what Tang of the Shang had carved on his bathing basin:
"gou ri xin, ri ri xin, you ri xin（苟日新，日日新，又日新 — renew yourself today; renew every day; renew again the next · our reading）" — renew yourself one day; renew every day; renew again the next. (Our own rendering, not a quoted translation.)
The meaning: if you can wash yourself clean and come out new for one day, then wash every day and be new every day. Tang had it carved on the basin — he saw it every time he bathed. From the day it was written, this line was never about a great undertaking. It was about one small thing you do every day.
The Book of Changes puts the same idea at the root.
The character yi（易 — change and growth · our reading） in its title means "change." But the Great Commentary explains it with a line of its own: "sheng sheng zhi wei yi（生生之谓易 — birth upon birth is what change means · our reading）" — that which gives birth to birth is what yi（易 — change and growth · our reading） means. Yi（易 — change and growth · our reading） is not change; it is growth. Change by itself is worth nothing. Only change that makes something come out of it is worth something. (Again our own rendering, not a quoted translation.)
The same book has four more words: "ri xin qi de（日新其德 — renew its virtue daily · our reading）" — renew its virtue daily. It does not say "change its virtue," and it does not say "replace its virtue." It says renew. Renewing is not throwing the old away. It is the old thing growing something new.
So daily renewal is not the pursuit of novelty.
This is where the two are most easily mixed up. The pursuit of novelty says, "I want to be different" — a new haircut today, a new way of living tomorrow, a new way of putting things the day after. It looks like movement, but it is turning in place: because the direction of that change is not growth, it is only not repeating.
Daily renewal says, "I am still growing" — today a little more understood than yesterday, a little more learned, a little less wrong. It looks slow, it is in the same direction every day, but it is alive.
Those two words, sheng sheng（生生 — birth upon birth · our reading） — birth upon birth — are in fact very plain.
Look at a tree. It has no need to pursue novelty; it grows every spring — a little, and then a little more. Come back in five years and you would not recognise it. It never once had the intention of changing.
People are the same. A person grows old not because he stopped changing, but because he stopped growing.
Here is the hard part: change is easy, growth is hard.
Change takes one decision — resign, move house, change circles — and everything is different at once. Growth takes the patience to do one small thing every day, and for a long stretch of time it shows no result at all.
So why did Tang have that line carved on his basin? Because the words "every day" are the truly hard part. To renew once, anyone can do; to renew every day is the work of a whole life.
The three words "you ri xin（又日新 — and once more again · our reading）" — renew again — say the same thing: not "renewing once is enough," but "after renewing, renew again."
The words gou ri xin（苟日新 — to renew oneself, daily · our reading） — we keep them as a saying.
They do not say what we do. They say what we hold to: a person does not have to hurry to become someone else; as long as he is still growing, he is always new.
Something old is not necessarily out of date — as long as it is still growing.