Working hard !?-1

I have met a lot people who tell me that they like to work hard. In job interviews, the avowal is more emphatic-“I enjoy hard work”.
Why would anyone want to work hard instead of curling up in the sofa with a favorite book or hanging out at the local with buddies?
The logic beats me.
I can understand a person who says that he works hard to make money. I can of course also understand people who work hard at their passion like artists.-in fact I envy them. But, ‘enjoying hard work’ – I am flummoxed.
I can only conclude, a la Sam Bahadur,” If anyone tells you he enjoys hard work, he is a liar or an algolagnist.”