2017 => now()

16-year old => 19 yo

Matriculation => Leaving college

Going college in my father rickshaw/auto => Working remotely

printing 'Hello world' in android phone => Using ThinkPad for day to day coding (still not comparable to MacBook but much better than smartphone :p)

'a shy person' => Attending Hackathons, local events, expanding my network and learning new technologies

Turned down on for "not enough experience" => Receiving job offers via LinkedIn and GitHub

Learning from my couch => Working from my own Home office

Knew nothing => Know something

Just write stupid small apps.

With lots of practice, you will eventually become a great developer. Although, you may never consider yourself that as you should always be seeking out learning more and more.

In the end, the thing matter most is your 'curiosity'. It's your curiosity about 'How things work' which will lead you somewhere...

Good Luck!