Not really a lesson learned, but a line that stayed with me. I forget which book it's in, maybe Post Office, but he writes about a winning streak he had at the track. It was so good he either quit or took a leave of absence from his job. He woke late, enjoyed steak and scotch, then ambled down to the track. And then he says, "it was a great life, and I did not tire of it."
All our lives, we're told that wealth won't buy happiness, that the only true fulfillment comes from hard work, and that getting what we want will only lead to misery. But here's Bukowski describing a life of utter self-indulgence, and saying he never got tired of it. Profound.