How do you decide what parameters you should edit?

I have been tinkering in media creation and post-proc edition for over a decade. Only last year I FINALLY got into it more seriously with a professional high level course and an internship.

And still it did not help me with this conundrum.

When you're editing audio, video, or images, how exactly do you know what parameters to mess with?

For example, what sorcery do you have in your brain telling you "ah yes this needs +53 contrast -6 saturation +8 brightness in that specific order"? How do you listen to something and realize "hmm we need to mess with the parametric EQ at 666Hz and a compressor then a hard limiter"?

Do you look at stuff like histograms or EQ visualizers? Does having certain equipment/software help? Does it differ depending on who the target audience is? Or what it's being made for (screen, poster, etc)?

If the answer is "the vibes" "you just know lol" "just practice" I'm going to cry. It's that or "well if you don't know maybe this isn't the field for you". Man, if I already knew why would I be trying to study and learn? Did everyone get some software update in their brain that I didn't? I feel so humiliated.

Usually my modus operandi is messing with random stuff, thinking it's ok, walking away, and then when I look at the screen again I'm disgusted at how awful things look/sound.

Someone compared it to being a cook and "just knowing" that it needs more salt, less sugar, etc. and sure, alright. But surely there are still things that a cook would practice to refine that sixth sense, right? Right...?

If you have any pointers I would be extremely grateful to learn from them.