I actually have a MS in astrophysics, never used it in a anything astrophysical. Now I am semi-retired living in a university town now. (PhD in engineering.) I might go sit in on some physics classes, depends on what wife tells me what my free time is.
Sitting in Physic classes sounds like fun. Not fun back when I was in college, though. The freshman and sophomore classes slam the students with information and it can be overwhelming.
What specialty in Engineering?