I am a software developer and I'm working full time so sc2 is just a hobby of mine, and it does not place very highly on my priority list. I never intended to get decent at sc and just played for fun. I didn't watch any tutorials or read any guides and just played games whenever I felt like doing so, which wasnt that often especially compared to hardcore people on this forum. Still, I kept improving slowly and soon I was out of silver and was approaching platinum. Then I watched FIlter's tutorials, smashed into plat and soon into diamond. One thing I find surprising is incredibly small amount of cheese I encountered. I got cannon rushed once, 4gated a few times and zergs did 2 or 3 baneling busts. I expected lower leagues to be cheese fest after reading some posts here but it wasn't the case at all. Terrans were the most aggressive in the early game, mostly with banshees and 1-1-1s.
Some stats:
165 1v1 games played,
0.45 games/day
99-65, 60% winrate
TvT 40-23 63%
TvP 34-20 62%
TvZ 25-22 53%
APM development
I have lower APM than almost everyone I play against, but my action redudancy seems to be quite small. Honestly I just don't have any time to spam even if I wanted to, there's so much to do.
Even though I'm in diamond now I still feel I know next to nothing about sc2. I suck at all aspects of this game, I can't even do drops because they are way too mechanically taxing for me (loading up, sending drop away, rehotkeying takes forever for me, I have no idea how pros do it so quickly). I always float thousands of resources and get supply blocked and my upgrades are always way way late. I know one build and use it in all matchups. Even so, it's fun to to play and I do feel somewhat proud that I managed to here. Hopefully I'll keep improving and make it to masters someday.
Finally, here's the win that got me promoted http://drop.sc/283127. It's a terrible game and quite indicative of my skill level :p.