It's not "not wanting to associate with you", it's more like:
Wanting to join an aggressive unfriendly nuclear-powered military alliance that's been expanding and approaching your borders for the past couple of decades.
That's not what caused the war. Interest in NATO membership came later, before 2014 there was basically no support for it in Ukraine.
What resulted in all this was that Ukraine was negotiating a very favorable trade deal with the EU. They had a presidential election, which was won by a guy who promised to be friendly with Russia, but also push through the trade deal. Only, when the trade deal was almost done, Putin called him, they talked for several hours, and at the end he declared that he was shutting down the deal, and would make one with Russia instead.
This was extraordinarily unpopular, because the terms of the EU deal allowed for Ukrainians to work as guest workers in EU. Doing that, you could earn more in three months doing unskilled labor than you could expect to earn in Ukraine with a degree in a year. Russia had nothing similar to offer. Because of this, there were massive protests. Then the president ordered troops to fire on the protests, and the protests escalated enough that the president fled. After that, Russia invaded Crimea and Donbass.
Two thirds of Ukrainians opposed NATO membership in 2013. Support only became a thing when there already were Russian troops in Ukraine.
