what to learn in my spare time?

[Aravind]

skills? computer skills? or learning algorithms regarding search Engine optimization.?
If computer, it is cool to learn ethical hacking.
If you know any of the computer languages, try to extend your knowledge in them by reach advance levels.
Try reasonable games and become expert in gaming. No fun. But you can learn a lot from Games.
How about musical instruments, if you are comfortable, like a keyboard.
Music is the one activity that involves the whole of brain and keeps you active.
Try solving puzzles. They keep brain active and you young.