[cheponis]

Also as an oldie, I'd say my productivity today is the highest it has ever been. How do I keep myself motivated? By constantly being a beginner. I do web programming, GUI programming, embedded systems, drivers, unix, mac, PC, bare metal, lisp, python, C, dozens of assembly languages, Verilog, hardware, analog, RF, antennas, etc.

In my opinion, you are just making excuses for why you are less productive than you should be; it's called rationalization. ;-)

My advice is to dive in to some area of s/w (or whatever) that you don't know at all (i.e. become a beginner) and see if that doesn't spark your excitement again. It does for me, over and over again!

[hacklite]

If you're constantly a beginner, your productivity is not going to be high. That's a given.

I'm not sure why you thought I'd need your psychoanalysis or advice :) We have different neurobiology.

I've dived into new things many times. It's just not exciting to me the way it was when I was younger.

[cheponis]

I think you're depressed.

But, you're right: why should I care?