I've only made indie games across the last 4-5 years... technically longer than that but that was all on one pygame project that I'm not sure should be counted as a game :D... Anyway during my time I've had lots of experience with different parts of game development, especially as I'm always switching between things! I've always found picking things up, especially things like programming, to be quite easy for me (I just enjoy learning), however it's taken me around 6 years to put these skills to something that looks moderately good (somewhat to do with things like art and programming also being taught at my school) - Also just released my latest game and I'm actually extremely happy with it, it shows how I've improved. Anyway I've never worked with others and that was definitely a mistake. It took me a long while to get into different communities and it's taken me until now to become properly active in them, ever since I started talking to others I've found the way I use the skills I'd previously learnt has developed much better, if that makes any sense... Either way that's my experience!