Did Jesus celebrate Christmas? Why?
No, because he was the object of Christmas celebration, as exemplified by the angels (Luke 2: 13-14) and the shepherds (Luke 2: 20).
And suddenly there was with the angel a multitude of the heavenly host praising God, and saying, Glory to God in the highest, and on earth peace, good will toward men. (Luke 2: 13-14)
And the shepherds returned, glorifying and praising God for all the things that they had heard and seen, as it was told unto them. (Luke 2: 20)
Angels are God messengers, they convey divine message from God. The angels set an example of celebrating Christmas for human. Then, their example of celebrating Jesus birth, Christmas, was a divine message from God. Consequently, following their example, i.e. celebrating Christmas, follows God’s instruction.