Shakyamuni Buddha searched for a way out of mental anguish and unease. Finding it, he tried to reduce it to its simplest form and taught this as Dhamma.
To wit: "Try to find Ego anywhere in phenomenal experience, either taken separately (in ordinary consciousness) or as a whole (in Dhyana)."
"Not finding Ego anywhere 'in' phenomena or even 'attached' to phenomena, wake up to That (ineffable) Awareness which beholds the search for It."
"Turning the light of attention 'inwards' to That, now realize that It cannot be contained in discursive thinking or conditioned experience."
Basically, those are the three 'effortful' opening stages of Pragmatic (also known as Original) Buddhism.
In a famous Pali sutra Buddha claimed that anyone who performed this kind of pragmatic self-inquiry with sufficient energy and focus would wake up almost instantly.
Note that beyond the opening three "self-inquiry" stages there are an additional three stages of Samadhi, culminating in Sahaja Nirvana.