Hmmm
Very few individuals have ever reached enlightenment by self cultivation.
The majority of people don't know where to begin, and I think its a foolish path to tread because most people can'y keep thier ego's in check.
Having a guru to show the way is usually the best and safest manner, as they already know the way. They don't make you enlightened, naturually one has to work hard by oneself to culivate a point where you can have realisation.
My ego would say that that I could manage it but my mind knows that it requires help from those further along the path than me, if I don't want to waste time.
Zen's humble beginings are in Chan Buddhism. Zen is Chan. The Japanese took Chinese Chan Buddhism and cultivated it themselves to call it Zen. Chan Buddhism is documented.
" Don't confuse yourself with someone who has something to say " - The Fall
" I do not like your tone/ It has ephemeral whingeing aspects " - The Fall
" There are twelve people in the world/ The rest are paste " - Mark E Smith