Maybe another way to describe it is - I understand my thoughts before I know the right words to use to describe my thoughts out loud. In conversation I sometimes find I'll start explaining something; only to notice that the words aren't the right translation for the concept in my head. "Sorry, thats not quite right - its more like ... this".
The other day I had a feeling which was a mix between boredom and anger. Like, a sort of judgemental boredom. I don't think english has a word for that feeling; but neither "boredom" nor "anger" would be a sufficient translation of what I felt. Its like that.
Or another example - I was practicing drawing yesterday. I drew a character's nose, but my line looked wrong and I had to rub it out and redraw it. I don't have any words for the shape my wonky line made. I couldn't tell you in words how it made the face look, or how it needed to be fixed. I could try, but any words I use would be an awkward approximation. I know exactly what was wrong with the shape. But words to describe it would be a sketch compared to my mind's photograph. (Except its not like a photograph either! Aah its happening now too.)
Lots of thoughts work the same way. At least for me. Is it really not the same for everyone?
thats your inner voice!