How did you become good in programming? I mean, if I take myself for example, I am self-taught (I come from Biology background and need to code for my Phd in bioinformatics), so I was not taught programming in a "proper" way.

Yeah .. my only two computer science courses were in FORTRAN (WATFIV/S, specifically) and COBOL during the '76/'77 academic year at Waterloo. After that it was whatever I learned whatever I needed to get the job done, with an occasional visit to K&R's excellent Guide to C Programming, and then learning on the job.

My degree in engineering helps -- learn whatever you need to, in order to get the job done -- that rule has served me well throughout my career.

• Perl? Didn't exist when I graduated in 1982. I picked it up in the late 90's when I used awk for a while, loved it, but found it limiting.
• Linux? Had a couple of false starts setting up SuSE Linux in the late 90's, and just didn't know enough to keep going.
• SQL? Knew enough in the late 90's to land a contract where I was learning it on the job. It's based on set theory, but then it gets complicated. And there are different dialects.

Really, it comes down to practice. I applied for a remote job about a year ago, and took the full week to do their 'Write us some code' example. Yes, I was out of practice. I plan to revisit that exercise to see how I could do it better.

Finally, like anything else, you need to be continually learning. I got an idea for a module yesterday, and went home to spend a few hours bashing up a prototype, which led me to a dark corner of Perl I'd never seen before (Symbol and qualify_to_ref). Fascinating. You need to always be stretching yourself.

PS Welcome to the Monastery! Becoming a member here has helped my Perl immensely, and I believe I've helped a few others.