If you do it right, by the time you hit 40 you understand that programming
doesn't actually move that fast. The superficialities are churning rapidly, but there's an underlying truths are quite stable. They are moving, too, but much more slowly.
For instance, take JS frameworks. On the one hand, they're churning so fast that nobody could possibly keep up with them all. On the other hand... they're all just shuffling the same basic primitives around in various combinations, and exploring spaces hardly any different than their desktop brethren 20 years in the past. There have been cases where I've successfully predicted the failure case of the latest JS wonderthingy just by listening to how it works. For instance, five minutes after I heard Node described I knew about Callback Hell, even though the term as such did not enter the lexicon for about another year and half. I could also tell you exactly what the proposed solutions were going to be, what their advantages and disadvantages would be, and almost completely called what order they would be tried in, because it was all just a recapitulation of experiences had in other communities. From the surface it looks like Node has been in wild churn, with more understanding it's merely a turn of the wheel of history.
As an example of the other side, DRY isn't going anywhere, and developing your DRY-vision is the work of a decade. (It goes way deeper than most people seem to realize.)