Sure. Same with the US Invasion of Iraq. "Six days, six weeks, I doubt two months" per Donald Rumsfeld.

But that was to sell the war. The real theory of the conflict was going to be that it would repeat South Ossetia / Abkhazia and Crimea. A rapid land grab intended to incorporate a heavily pro-Russia border territory that wouldn't escalate for fear of reprisal.

What Russia got was an enormous escalation (fueled by NATO) and a protracted conflict. But the conflict didn't benefit Ukraine, for the same reason an armed revolt in Crimea or Georgia wouldn't have benefited either of those territories. All it produced was a new Chechnya / Afghanistan. A killing field that obliterated the accumulated wealth of generations and the lives of hundreds of thousands of people. Nobody is coming out of this ahead.