There are two kind of programming knowledge:

a) the kind of knowledge that never goes away. To know how a linked list works or the time complexity of randomized qsort is really valuable. The more you can know about this stuff, the better.

b) non-general knowledge, that is, knowledge that aliens from beta-orionis can't know about: they probably know about qsort, and prime numbers, and linked lists, and parallelization. This are concepts not invented, but... mostly discovered. Instead non-general knowledge is how to configure Apache, how a particular programming language works (and not the general abstraction it implements), and how Microsoft technologies work.

You are required to learn a lot of b-type stuff, but the lesser the better, so you have to learn environments, languages, that are powerful, cheap, affordable, available, reliable, ...