You were able to learn to train efficiently throught the forum? Wow that's pretty cool. How ?
Well, basically, I would find out hints from people which my instructor didn't give me. For example, there would be advice about certain things which is phrased differently which helped me overcome my problems easily.
Also, there are lots of resources on how to strengthen yourself, improve your endurance and improve your flexibility which helps to learn techniques easier and faster.
Sure, it's no replacement for proper training but knowledge like that can help you improve more quickly.
Better to benefit from other peoples' experience than be ignorant about the wider world.
(Website by Marc MacYoung, not me)