Kyiv spawned Moscow. I did not know that. I am going way back now.
For the Russian collective memory Ukraine is the place of origin at least on the European side of things.
I doubt that is true for the Ukrainians. It is like hey we know you are family but how many cousins removed? No I am not paying for dinner. Get out.
The other thing many Russian troops maybe coming from the Asian side of Russia. How much of a bet that makes them second or third class citizens in Russia? Why would they care to fight? Ukraine is now where they came from even 1000 years back.