Russian here (to be precise Russian Canadian of Ukrainian descent :-)
There is a saying in Russian: if a stranger, on your question "how are you?" (ru: как дела?), starts explaining in details what is happening with him/her - please know, you've met complete idiot.
So I am classifying that 'how are you?' as never ending test of my life position :)
Ukraine has a lot of Russian speakers, I would think most of the population can actually speak Russian, or a mix of Ukrainian and Russian (given the similarity between the languages)... on TV, it's common for people to switch languages mid-conversation, for example...
With that said: Ukraine is a big country with a very strong culture that differs from Russian culture in (for us, foreigners) subtle ways. Near the border with Russia, however, Russian culture is stronger, hence some regions even associating themselves more strongly with Russia than with Ukraine (Krimea was one of those regions, by the way, which may explain to people who are unaware of this situation why there was no popular revolt - quite the contrary - against the Russian occupation).
Yes, they're quite different and similar at the same time. More than that, Russians are not all the same (Southern Russians are more like Ukranians, Siberian Russians are not very similar to Moscow Russians and so on). With Ukranians, you have at least two different cultures — east (relatively similar to Russians) and west (these guys were more influenced by Poland etc.). So, yeah, Russians and Ukranians are quite similar (they are two Slavic nations with common background), but there are a lot of differences too.
Countries and identities do not have a 1-1 mapping. This has and is causing a lot of issues I’m the world. Or is used to create a lot of friction by people that wants that.
Rus (as statehood) originated in Novgorod (originally as a republic, btw). Then center was moved to Kiev. Then to Moscow.
At those times there were no such entity (and ethnicity) as Ukraine at all.
Significantly later it was Cossacks republic on part of territory of modern Ukraine: https://en.wikipedia.org/wiki/Zaporozhian_Sich#/media/File:0...
At that time it was no Ukrainian ethnicity too. Cossacks (armed settlers) were multiethnic by definition - members were ethnically Rus, Poland, Tatar, etc. from all close and far neighbors as this was area and society of refugees. That mix eventually transformed into separate ethnicity.
Ukraine as an ethnicity is relatively new entity. And needless to say that Ukraine as an entity with definitive borders was a communist invention, Lenin and later Stalin have drawn its borders - Russian Empire had no division on ethnical principles.
There is a saying in Russian: if a stranger, on your question "how are you?" (ru: как дела?), starts explaining in details what is happening with him/her - please know, you've met complete idiot.
So I am classifying that 'how are you?' as never ending test of my life position :)