Is acceptance really such a childish concept??

In my 20's and started rewatching sex and the city and i got hooked on this quote from the past 20 mins

Where carrie says

"When We Were young ,MARLO THOMAS sang to us about accepting each other and our differences. But then we got older and started singing a different tune.we stopped celebrating each other's life choices and started qualifying them.

IS ACCEPTANCE REALLY SUCH A CHILDISH CONCEPT?

WHEN DID WE STOP BEING FREE TO BE YOU AND ME.?