In any good programming reference, you will read that a developer has to document his code, not only for him/herself, but also for the person who, ten years later will be asked to maintain it. This would, of course, be made easier thanks to a good documentation of existing code.
A meme is an idea, behavior, or style that spreads from person to
person within a culture—often with the aim of conveying a particular
phenomenon, theme, or meaning represented by the meme.
I retired a year and a half ago after having worked for twenty-six years as a programmer for Apple. I’m not sure which would have been more surprising: if I had continued programming in my spare time after I had retired or if I never programmed again.