I beseech you to look up the Cave Man Theory. It states that work is part of humankind, dating back to the Stone Age. It also states that humans can find pleasure in work, finished or unfinished. Man's essence is in work.
And humans are the only species ON EARTH that bitch about work.
Yes, but, no. There's a reason it's called a "theory" - to me it doesnt prove anything, save that there is an evident paradox... which it would take yonks to resolve. Just another of those mysteries surrounding mankind.
As a footnote, I would add that pleasure is immaterial. Man may very well find pleasure in pain.