@yeto
Without getting in count the bad words you said to an older member of AutoIt, you have to think and know that everyone has started from zero.
The road everyone builds up during the spare time, or whenever you can take a look at Help file, at Forums, and so on, depends from what everyone wants, so, if you would really whant to know more about the functions used in the script above, why do they work in that way, and how can you use them at your advantage, then you need to take a look at the Help file, try some scripts, study the behaviour of the functions, and everything else behind the scenes.
The limit is the willingness everyone puts to see what's going on over the horizon