Their sons, daughters, grandsons, fathers, and other extended relatives are currently embroiled in a bloody, extremely devastating, costly war that has seen over 100,000+ of their countrymen wounded, blown up, shattered by missile drone strikes, or mortar shells, bodies riddled by bullets, picked off by Ukrainian snipers, sappers for a war whose reasoning defies logical sense and reasoning, and is based around centuries-old pan-Slavic ultra-Russian nationalist aspirations, fanatical dreams of expansionism into Middle East, conquering Istanbul/Constantinople, extending Russian religious, economic, or cultural influence further into Eastern Europe, South Asia, and even parts of mainland China.
These same ideals were the basis for three wars fought between Tsarist Russia and Ottoman Turkey throughout the 19th century (including the Crimean War). Putin is a huge admirer of Czar Peter the Great, who originally opened Russia to Western influence and liked to use dental pliars to pull people's teeth if they were sore and ordered Russian Orthodox priests to shave their beards, and Putin doesn't believe Ukraine has a legitimate, sovereign right to exist outside of Russian domination, control, or influence.
He's bothered because he perceives Ukraine as being too pro-West, and wanting to move closer to NATO and EU and decided to invade to prevent that.