Why don't Christians celebrate Jewish holidays?

I grew up as a child of a Catholic-raised atheist mother and Jewish agnostic father, so while I celebrate several holidays, my understanding of their religious context is very surface level.

I know Christianity branched out and evolved from Judaism, and that Jesus was Jewish, so I find it confusing that Christians would not celebrate Jewish holidays. Is a holiday like Hanukkah, for example, not celebrating a miracle of the same god? Do all Old Testament observances and rules not apply to Christians?