I don't know the criteria for did off the top of my head, so I cannot answer either or not trauma is a deciding factor. But I'm not quite sure if that is what you are actually asking. Only a licensed professional can diagnose it, no one here can do that for you.

As for a happy childhood and dissociation, I think we all dissociate to a degree. It's the severity and impairment caused by the dissociation that makes it a problem. Daydreaming is often considered dissociation, as is that state you might reach while driving a familiar route-you get to your destination but can't recall specifics of the drive. These are all normal dissociation that would not be categorized as a disorder.
DID is categorized by distinct "personalities" that step forward at different times. It may or may not involve co-consciousness, and is often times very disruptive to an individual's life. DID is actually pretty rare overall (only a small portion of the world's population is diagnosable), while dissociation to a milder degree is a petty common thing.
If you are concerned about dissociative behaviors, I would suggest seeking out a professional to talk to about it. They would be able to explore the feelings you are having, and be able to give you an idea of how to proceed.