how do you explain them giving it up so easily
I like how the soviet born Vlad Vexler puts it... (other former soviet peoples) have not really dealt with the trauma of the Soviet Union and they carry it around with them and it affects them in various (mostly bad) ways.
russia on the other hand, over the last 20 or so years, have been seeing a very bad analyst who's convinced them that nothing they did in the Soviet Union was wrong and their problems actually stem from the dismantling of the soviet union rather than the daily dysfunction that defined it.
to put it another way.... every country (to work as a country) has a story that they tell themselves and this story changes over time.
In the 1980s Poland's story was "We are surviving until something happens to change things" then it was "We're going to return to our common European home" and now it's "We are safeguarding western values".
I don't know what Ukraine's story was before 2013 but then it became "We're going to join the west!"
As Galeev wrote, until the early 1960s the USSR's story was "We're building communism!" and then when it became all too obvious that that was terrible the deliberate choice was made to change the story to "We beat the nazis in WWII!"
After the soviet union collapsed russians didn't know what story to tell themselves to replace that... "We ran one of the worst countries in the 20th century"? "we failed at everything but repression"? so they're still stuck with WWII... putain's goal has been to build on that and to make their new story "We can repeat!" or "We don't leave our own!" but most russians aren't really buying it in active terms.
russia is definitely a lot worst off than it could have been but that's due to the choices that russians make every day and continue to make.
Ukrainians, like Poles, have no problem in standing up to a government that doesn't meet their standards... russians.... have yet to learn that which is kind of pathetic.