What a title.

The words that come next will shock you!

Conflating two concepts can be funny (e.g. puns) but this isn’t that. “Dereferencing a movie ” has no meaning outside of manual memory management.

I understand humour is subjective but some jokes aren’t as strong as others (and some jokes aren’t jokes at all).

I personally don’t find it funny because these types of jokes essentially boil down to “I used a concept outside of its context, and for that reason alone it is funny”. However, with a lot of these jokes the context is so narrow (i.e. programming) that they are almost universally not understood by wider audiences.