Also as things get older they get better and better explained. Some things, like relativity are simple mind-blowing concepts, but other very important aspects

Also as things get older they get better and better explained. Some things, like relativity are simple mind-blowing concepts, but other very important aspects of physics can feel like no one is doing such groundbreaking work because you're actually looking at a modern interpretation of something which has been condensed over a century e.g. a lot of papers from the early 1900s are very long winded, so the utterly beautiful ways they may be now treated (Noethers theorem may be an example) are not representative of how they burst onto the scene 100 years ago.