By the standards I've had previously, I totally am. These standards were:
From the age ~18 - now:
Adults are financially independent.
From infancy to now:
Adults can choose whether to eat dessert before or after dinner.
While I believe both of those things are still true, there must be some other element as well. I'm financially independent AND I sometimes (often) eat dessert before dinner (or eat popcorn for dinner), but I don't think I'm really an adult.
With any luck, I never will be.