Oh damn, I can't remember exactly when. I used to write short themes and melodies on sheet music back in my late-elementary school years (2005-06) after I started taking piano lessons. In late 2007 - early 2008, I started using a MIDI-based composition software with a staff editor, piano roll editor, and a channel editor; it only saved as MIDI files and was pretty terrible overall, but I feel like my best songs composition-wise were done on it (but MIDI sounds like shit). I upgraded to MusicStudio on iPod in early 2010; it lacked some of the nice features my MIDI software had (like automation - ugh, I hate not having automation), but sounded better and had some better features and songs could be exported as .wav, .midi, and .mp4 files. It wasn't until the very end of 2011 that I got FL Studio, and I've pretty much taught myself most of all the techniques I use.