Why is it that I have such intelligent conversations with myself in my head that actually make sense but am never able to say them out loud?

I’m not in your head to be able to comment with actual knowledge of your case, but a few things come to mind.

1) The mind has incredible capacity to do huge amounts of complex parallel processing with itself and the rest of the nervous system. You can think about several things at once, while doing other tasks, and with your subconscious doing yet other things, while processing vision, sound, music, and being aware of your surroundings, all at the same time. That involves probably millions or more pieces of information per second. Meanwhile, your mouth can say a few words per second, and processing that actually requires slowing down and keeping track of the words you are saying.

2) The difference in speed between the mind and the voice is huge, and one thing that humans don’t do all that well is short-term memory. So you may be able to do very complex thinking and then forget it before you can say it.

3) Converting thoughts into effective language is also a skill, which takes a lot of practice.

4) Sometimes ideas seem to make sense when your mind has a flash of inspiration (or especially, I find, while dreaming), but then when you carefully try to set them to words, you may discover they don’t actually make full sense under careful scrutiny (or you forgot or misremembered the brilliant parts by the time you got them into words).

5) Probably other things. :-)

6) Welcome to Fluther!

My ex-wife used to “prepare” for conversations. She would run a potential conversation through her head until it was perfect for her. The problem was that as soon as she started the conversation, the other person would say something “off script” and the entire conversation she had planned was off.

Try committing your thoughts to paper so the world may benefit from your “enlightenment”.

That’s just the way it is when you talk to yourself. You have a conversation with a person of equal intelligence.

Because when you have those private conversations, you don’t require the same vocabulary skills as when speaking to others.
For instance, if considering a painting, you could think to yourself, that blue reminds me of the sky that day.
To explain to someone else, you require a variety of adjectives and nouns to give an impression of how profound was that day, for you. You need to describe the blue. You need to describe exhilaration with things like, “wildly amusing”, or “deeply moving”.
To convince yourself of something only requires the moment it takes you to have an emotion. Giving that emotion to someone else requires paying passage to their emotions.

I agree with @stanleybmanly about putting thoughts into writing, but not for quite the same reason. Writing can be a very useful too for organizing thoughts. One thing that it does well is to keep you from thinking the same thoughts over and over again. Once it is on paper, it is accounted for. Writing also allows you to edit and correct yourself.

I have heard it said that using pencil or pen is more effective in the thought process than a keyboard. I much prefer using the computer.

Just a day or two ago I tackled a recreational logic problem by writing my thoughts in a Word document. It took me a while, but I finally solved it. I don’t think I could have done it without writing my thoughts, even though the problem could, at least in principle, have been solved without writing anything down.

I once shared an office with someone who I had a lot of trouble understanding. I started to use the whiteboard to diagram what he said. It was understood that I was not being rude, but making a genuine effort to make sense of what he was saying. After a month or two, there was a noticeable improvement in how the guy expressed himself. I no longer needed the whiteboard. And no, there was no change in my listening ability.

@Camisarinad Why is it that I have such intelligent conversations with myself in my head that actually make sense but am never able to say them out loud?

If you were to type these intelligent conversations you have with yourself here on Fluther then you wouldn’t be saying them out loud.

Do you any specific examples that you would care to provide as evidential support for your contention?