I've been programming for X years where X is a surprisingly large number.
2012 - 1975 = 37
Some conclusions may be in order.
First, most people don't program that long. The conventional wisdom is that you "move up" into management long before you've been coding for 37 years.
There is a lot of magical thinking about creating "career ladders" within teaching, in part because there is a lot of fantasy about how other careers work. Mostly you just go into management, aka, administration.
There are, I guess, top doctors and lawyers who still do high end medical procedures and mix it up in prominent cases, but few careers have "ladders" which allow one to primarily continue doing the core task.
Can you think of any examples?