I began testing Linux environments 14 yrs ago when I was in middle school. I had spare time during summer months and holidays, so i donated a lot of time to this hobby. Back then, there was this distribution called Gentoo offering optimized systems and applications for the respective hardware by using streamlined manual compilation methods.
Of course, I had no clue what it was all about, but I wanted to be a cool hacker, so I followed the guides and tried my luck. But when I got into it, Gentoo was extremely fascinating for me due to the fact that all parts of an operating system were broken into parts and you, as a user, had to put it together piece by piece. So, after the first 12 hours of the installation process, i was presented with a command line - and I felt like a hero.
In the following years, I reinstalled the system several times, I managed to cut down installation time of the core system to about 8 hours and, eventually, I was able to configure X, the display server, correctly and began using window management systems like fluxbox and terminal emulators - actual graphics and stuff!!
Years went by and distributions like Ubuntu got momentum. If Gentoo is the raw, Ikea-like version of a Linux distribution that you have to build yourself, Ubuntu is the ready made all-in-one-wonder that just works (more ore less - take this with a tablespoon of salt ;) - also, there exist a lot of different distributions out there that offer similar things). Suddenly, using Linux got very comfortable for me and aside from the main system and the kernel itself, many of the programs got way better, for example Open Office, the nowadays Libre Office and also Blender, the 3D CG modelling and animation software, started to grow pretty fast.
I continued using different Linux distributions alongside Windows, which I got mostly for gaming and specific programs (for graphic design or audio editing for example) that were not supported on linux at that time.
There were distributions everywhere, focusing on specific functions and qualities: During my education regarding media techniques, I had a project where I recorded, edited and mastered a song for a local band - and I did all of it on Linux using a specialized distribution with characteristics like a low-latency kernel (meaning little delay or input lag), a software based, internal audio routing system and pre-installed software like Ardour or Audacity for recording and editing. And it worked! All of the parts could be done on a Linux system. And the connections and applications got better since then.
There are many reasons for using Linux over other operating systems, but the main cause, for me, is the flexibility and the limitless possibilities for customization. At the time being, I switched to Fedora, enjoying mainly the straightforwardness of all of the included tools like git or ssh. If you haven't done it, you should definitely try it out!
Btw: If you're interested in how many distributions there are right now: Take a look at this. :)
Actually, I just wanted to write about how my desktop looks and post some pictures - don't know what went wrong. :D