Nobody had ever called me by my real name until college. It's easy to see why; I didn't have a real name until then. At the time, I didn't even really realize I was being called by my real name. But by the time I graduated, I realized that I really much preferred being called by my real name: Embolalia (or Embo, for short). Bear with me.
Hopefully, you don't need much convincing that Elsie is my real name. You may be held up on the fact that I was not given that name at birth, or that my legal name is not (yet, as of writing) Elsie. But does that make it unreal? Does it make it fake? Is it false, feigned, untrue, imaginary, fraudulent, or any other antonym of real?
My deadname always felt feigned to me. Even before I realized my real gender (nobody's questioning my use of "real" there, right?), I knew it wasn't my real name. I tried using the diminuative form, a truncated form, and the full form. All of them felt off in some way. Whenever I gave that name, it felt like a lie. When I introduce myself as Elsie, it feels like the truth. That simple fact makes it my real name.
At some point in college, I started getting involved in OSU's Open Source Club. Since (in true FOSS fashion) a lot of the conversation happens over IRC, it's very normal there to call people by their screen name. There were more than a few people whose other names I never actually knew (or did, but only after I was reminded). I had already started using Embolalia online by then, so that was the name I used (and still use) in the IRC room.
I didn't start out intending that people would call me that in person. It just sort of happened. I certainly wasn't going to "correct" anyone - not for a name that wasn't real anyway. I got used to people calling me Embo, and started introducing myself that way to new club members, and later to some people outside the club. It acquired that feeling of me-ness that'd always been missing from my deadname.
When I introduce myself as Embolalia or Embo, it feels honest in exactly the same way that introducing myself as Elsie does. When someone calls me Embolalia, it feels like they are referring to my actual self in the same way it does when they call me Elsie, and the same way it doesn't when they call me my deadname. If I fuck something up, it feels just as natural to say to myself "come on, Embo," as it does to say "the fuck, Elsie." It is just as much my real name to me as Elsie is.
I see no reason why a person can only have one real name. Nor do I see any reason why a name can't be real just because it's used primarily online. Identities are complicated, nebulous things. In the same way that I use a variety of terms to identify my gender, depending on who I'm talking to or how I'm feeling, I also use a variety of terms to identify myself. Those terms are equally my name, and are equally real. They are my real names.