Star Trek: 10 Things You Didn't Know About The Soongs
4. Noonian Soong Didn't Want Data To Be Creative
Data learned a lot about his history when he met Noonian's former wife, Juliana. One of the things she told him was that Noonian didn't originally want him to be creative or artistic in any way.
Noonian, at the time, didn't think that Data would ever be able to have real emotions, so he thought programming a creative passion would be irrelevant. He figured if Data would never be able to enjoy his art, then there wasn't really much of a point to it. It was Juliana who finally convinced Noonian to add that part of Data's personality.
This is why Data was always so artistic in his off-time. He played violin, wrote poetry, and painted, despite not getting any joy from his creations. He did however admit to Juliana that it was during his creative endeavours that he felt the most Human. After all, self-expression is one of the main things that separates sentient beings from mindless robots.