Neuroscience! Specifically I'd learn more about the effects of technology and social media on the mind. From the marketing aspects to the future of younger generations, and the influence of doomscrolling and tiktok on the human brain. I actually read about a study which showed the difference in brain patterns between an individual who used no social media and one who did. It's interesting to think about the lasting effects that technology has on humans.

I would choose the matter of space. something about learning about space and the intense confusing part of atoms that are never touching yet the human mind makes an illusion to create colors, objects, touch. everything. it's so fascinating. so just science but more specially space science.

Anything math related

I want to know psychology more so I understand people's emotions because honestly? I have a lot of friends who are always going through shit and hell on Earth and I haven't, so I wanna learn that better.

biology

I would love to know more about deaths and what people feel/go through.

rocket science

How to beat every video game level or how to cook

The universe

probably smth like history or biology