I do the same thing too. Heck, we - I AND my tulpas - sometimes make up conversations with imaginary people for fun. (Or, more often, for practice figuring out what to say before actually having a conversation with someone about a thing.)
But there’s a big difference between the ones we imagine, and the ones who are tulpas.
To explain how, I’d like you to do a little thought experiment.
Imagine, just for a moment, that you are telepathic.
If you could actually communicate with other people using just your mind, how would you determine the difference between imagining what people are thinking, and actually hearing them think?
Ponder that for a moment.
So, for starters, when imagining, you are in total control. Even when you pretend that you don’t. You can cut off the conversation at any time. Change topics. Alter what the imagined person said. Go back rewind and unsay something that you said that felt unsatisfactory. You can change what the imagined person feels or thinks or believes with just a push of your mind.
If you have a good imagination, you can even forget that you’re imagining. You can even imagine that imaginary person pushing back at your attempts to change their mind.
You can’t do that with a real person.
You start being able to actually talk to people telepathically - in this little thought experiment here - and you’re not going to be in control of what they think or feel. Try and they’ll fight you on it. You try and rewind the conversation, they’re not going to just forget and roll with it - they’re going to remember. Just like you can’t always predict what a real person physically says, you won’t be able to predict what they think at you either. They’ll surprise you. Argue with you from their own perspective. Remember things you don’t.
And that’s what it’s like to have a tulpa in your head.
They don’t have a separate physical body, sure. They use the same brain you do.
But with an imagined person, YOU are doing all the thinking for them. You’re in control.
Tulpas do all their own thinking. They control their own selves. They have a will of their own. You can’t force them to say what you want to hear, can’t make them feel what you want them to feel. You push them, they’ll push back - whether you want them to or not. (And if you push too much, you’ll probably upset them and then have to talk it out and apologize.)
Talking to them feels like talking to a real person, with all the spontaneity and misunderstandings and not always seeing eye to eye stuff and all that jazz.
Talking to an imagined person feels like puppeteering by comparison.
That brings up one last point - when you stop imagining, when you take the sock puppet off, that imagined person stops existing.
Tulpas never stop existing. Sure they can go quiet or leave you alone/give you some privacy or “sleep”, but they always Exist. They’ll interrupt you when you’re not thinking about them (once they learn to, anyway.) They’ll point things out that surprise you because you didn’t think they were paying attention then. You’ll want to drop a conversation out of boredom or frustration or whatever, they’ll keep it going because they’re still interested.
Talking with them isn’t like sitting down and mentally envisioning someone. Someone that you conjure into existence with your imagination, and when you turn your attention away they vanish.
Instead, it’s listening and talking to a second mind that, once solidly made, always exists alongside your own. And WILL always, unless you intentionally set out to destroy it.