4 years? I've just checked and its only got 78 moves.... I shudder to think how long it'd take you to finish our yang style 108 long form!
Well done mate - I got my first student all the way through his first form a couple of months ago and he said he felt like he'd just graduated from uni! When I finished my first form it felt like a real achievement, far more so than any kata I've ever learnt. I don't know, there's just something very special about finishing the form. Trouble is, as my sifu rightly said, "Now the real work starts!"