Quote from : Citations: A Brief Anthology Book

Ah Buddha, you boastful charlatan. You may have learned nothing after 6 years of suffering, but then what of 7 years? What of 17? What might you have learned from a lifetime of pain? [...] From what I can tell, the wisest man in all these scriptures was the first person Buddha ever tried to teach - an Ajivika named Upaka. Buddha bragged to him of how he achieved nirvana, to which Upaka simply replied: "That may be so," and walked away.