City lifted the famous trophy two years ago to herald their arrival among the elite of the English game, with their victory over Stoke ending a 35-year trophy drought.
Having failed to defend their Premier League crown and slipping out of the UEFA Champions League at the group stages, the FA Cup could be viewed as a consolation prize in a disappointing season.
Kompany disputes that and is determined to make the most of the occasion when City face Wigan at Wembley on Saturday.
The skipper said: "Every single time it is something very special. You shouldn't take these kind of games for granted, they don't always keep coming.
"It is unbelievable for us to do it again, and for the fans it is unbelievable as well.
"We have to be respectful of every trophy we can get. If we win this one it will be massive for the club and something to cherish.
"If you win a trophy you should celebrate it, you consider it as a great achievement."
City are firm favourites to defeat a Wigan side struggling to avoid relegation, but Kompany remains wary of Roberto Martinez's men.
"They are one of the more difficult sides we have played this season," he said. "You can see it's a team that doesn't fear keeping possession.
"When it's going well for them they are a very difficult team to play against. We have to be careful."