Normal people can celebrate without alcohol, very easily. They might drink, but they put the champagne glass down after a couple or one refills, or they may not even finish the second glass.
And, they have a great time.
It sounds like you have connected the word "celebrate" to "drinking". They are not connected. I see people celebrating and having good times without drinking, or drinking moderately, all the time.
It's just a matter of learning new habits and new ways of thinking.