In my industrial mechanic apprenticeship I had a stay in the maintenance department. In the time had to clean out a several hundred liter tank of spoiled cooling lubricant of a CNC machine. If not maintained properly it becomes a breeding ground for bacteria and fungi and it almost made me puke the first time I broke the surface of the waste at the bottom of the tank after pumping the fluids out. It didn't get much better when I had to shovel out the rest of it.
I will never work in maintenance again.
(Edit because I tried something short because I wasn't able to comment here last time I tried)
"In 2008, RT-70 was used to beam 501 messages at the exoplanet Gliese 581c, in hopes of making contact with extraterrestrial intelligence. The messages should arrive in 2029." - https://en.wikipedia.org/wiki/RT-70?wprov=sfla1
As someone who learned subtractive machining (milling, turning etc) I find additive machining very interesting. My friend bought a cheap printer recently and I'm excited to try it out.
When I played with my much older brother when I was a lot younger I never let them him play with his black deck that was built around his ivory tower card because it was so annoying. I still almost always lost but at least I had fun.
The South Koreans did the same in Vietnam and it is said it kickstarted their economy, maybe it's the same here.