But people don't change.
I think that your statement is inaccurate.
Though we might possess inherent data that allows us to maintain a certain similarity of form and function, physically we are vehicles of constant change, absorbing and processing nutrients in order to continually renew ourselves.
Similarly, our on board computer also has a basic predetermined operating system, and also a formatively acquired set of well established core knowledge that is not so susceptible to change. As we progress, we are still subject to a continuous input of new data. which will nonetheless have an impact upon ongoing performance.
Of course, we also change considerably as we age.