In the known history of human existence, the Buddha's enlightenment, in my opinion, is our greatest accomplishment. The selfless pains and trials he passed through, without the aid of instruction or guidance, in relentless effort to understand the condition of suffering for all beings.
Through the round of many births I roamed without reward, without rest, seeking the house-builder. Painful is birth again & again. House-builder, you're seen! You will not build a house again. All your rafters broken, the ridge pole dismantled, immersed in dismantling, the mind has attained to the end of craving.
—Buddha Dhp 153-4