I think in this case it is more apt to realize that the artist painted this on the wall of his dining room in his house where he never had any visitors. The definition of "happiness" in this context would have to be a tad....malleable though.

Although he initially decorated the rooms of the house with more inspiring images, in time he painted over them all with the intensely haunting pictures known today as the Black Paintings. Created without commission for private display, these paintings may reflect the artist's state of mind late in a life that witnessed the violence of war and terror stoked by the Spanish Inquisition.

https://en.wikipedia.org/wiki/Saturn_Devouring_His_Son