My variation on that is realizing that I know have enough money to buy the expensive, specialized, books I want to read without having to debate it with myself.
Getting one or two book I love every month fills me with both joy and knowledge.
My variation on that is realizing that I can now buy the more or less expensive books that I downloaded illegally when I was a teenager.
Most people in the publishing industry don't realise that I probably wouldn't have got into the industry or wouldn't have reached my current level without some pirated books.
I can now afford without many problems to spend 60+ euros on a book and I'm doing it. Not often, but I'm doing it (books take time to read :) ).
My last purchase was advanced programming in the Unix environment (~65 euros), about one month ago, I'm currently at about page 200 out of ~970.
O'Reilly is going to get so much money from me in the next years... They kinda deserve them lol.
Getting one or two book I love every month fills me with both joy and knowledge.