Of course, it matters so much to me to be convinced that the skill sets I'm learning today would be relevant and still be lucrative in future.

Two sad reminders that hit close to home: In 2004, a friend of mine went to an Information Technology training institute and studied computer engineering, with focus on desktop PCs. Now, the usage of desktop computers is in sharp decline, as majority of people favor mobile computing devices. And there's no indication of any form of desktop resurgence. My friend is currently out of job, just because what he learnt is no longer relevant in today's world.

Another friend dedicated many months learning how to build cybercafe billing software. And he succeeded in developing one he was making huge amount of money from. Now Internet cafe business is no longer lucrative and many of them have shut down. So, not many people are buying my friend's billing software, and he's broke.