it really do be like that

Any electronic thing

"Hey, this thing I like is really cool, I wonder how it works?"
Math, loads of math. It is always like that.

I did a double major in college.
In my computer engineering courses, I learned digital signal processing, and then took a follow-up course on signals and systems because I enjoyed the material and I had an eye on robots, because robots are dope.
Imagine my surprise when I got to 4th year and I suddenly found myself using the exact same math to handle thermal and fission product neutron poisoning feedback in my nuclear reactor physics courses.
- desire to learn more DSP maths increases
  But seriously that's really cool! You also sound really cool, do you mind me asking where your studies have taken you? I'm looking at going back to study soon, potentially for compsci and mechanical engineering but I'm torn between a lot of different degree at this moment
  
  I'm currently working on a government funded project to develop a robot to locate nuclear contamination in soil (for cleaning up the Hartford and Savannah River sites, where we used to make nuclear weapons). The idea being that we use robots to perform these surveys rather than handheld detectors.
  My recommendation though, is focus only on one thing. Having two degrees has not made me particularly marketable, it is certainly unique, but HR doesn't actually seem to give much of a shit. Instead, it's much better to focus on one thing, get a Masters or PhD in it (double degrees also suck for this as well, because you don't have time for research and publishing when you're graduating with 195 credit hours taken out of 128 required, so even if you have a good GPA it's hard to get into grad school).

When I think of digital signal processing I think of things like audio and Fourier transforms. In my experience there's quite a bit to graphics programming that's different from that. A lot of shader code is linear algebra / matrix math, and physics equations for light. There's also a lot of thinking about memory layouts and how to reuse calculations as much as possible.
I say this as someone who does a lot of graphics programming in my job but failed "Feedback Control Systems" the first time through.