And food/edible items (how we've gone from eating leaves/dead dinosaurs etc, to all the stuff we have today)
Not to scoff at your choices, but there was a gap of a fair few million years between the last dinosaur and the first human.
5. Combustion engines
I think it is bloody insane how someone managed to work out that not only was this possible, but that they actually made it work. The petrol engine and the steam engine fascinate me. Fuel goes in -> fuel reaction moves some parts -> witchcraft -> movement.
4. History and politics
How can you not be astounded by the events which have led to our respective societies being where they are now? Just finding an interesting person or event and comprehending the knock-on effects is mind boggling. In layman's terms, what really kicked off World War I was the assassination of Franz Ferdinand, right? Might never have happened had Bismark not excluded Austria from his
Grossdeutschland concept. Having Austria as a willing member of a single German nation state could have brought more stability to Austria's eastern territories.
3. Etymology
I am fascinated by language. I speak two fluently, and know a little bit of a further two. What I find particularly interesting is where these languages come from and at what point they overlapped, or at what point they diverged. The Latin influence on any Western European language cannot be overstated. The anomalies, too. 'Window' comes from the Latin
fenestram and translates as
Fenster (German),
fenetre (French),
venster (Dutch) and even as
ffenest in Welsh, an ethnic group that has very little Latin influence. But English sidesteps all this and takes its word, window, from the old Nordic languages. Why? Ah, that's the beauty of language.
2. Accents
I can't even explain this one, but I am utterly astounded at how people can interpret the same language in different ways even on a purely phonemic level. I will talk about accents with almost anyone I meet. Beware.
1. Human relationships
People's wants or needs to not be alone. And what sort of person they desire and why. Who isn't interested in or interested by that?