Or are you created shaped by the thoughts that appear in your mind?

This is the key question that can also be phrased as: "Do we have a free will?"

I think we must have some degree of free will so that somebody or something else is not living our lives for us. It is necessary to be a little bit free to be a "being" at all.

A free will is a mystery to science, which has so far seen only rigid causality and hypothetic randomness.

A closely related question is: "Are brains the source of thought or a medium of thought?"

I think thoughts come from memory, personal and racial, but are we anything different from thoughts? Or a knot of thoughts thinks?

Thinking needs memory and works with memorized things, but if thinking is dictated by memory, we become automatons.

thoughts comes and goes, all the time, some thoughts stay as some kind of "truth" in us, we feel those thoughts are correct, some thoughts might be evil kinds, and must be taken out of mind, and I always go by humour or good music.

Agree Puti, thinking needs memories, but analysing´s leads us to the future too

Automatons, thats what most of us are. Is there a thinker that is not a structure made up of thoughts?

If most of us, but not all of us, are automatons [automata?], how can we tell who is and who is not?

I would rather say that a structure made up of thoughts is an opus, be it a book, a film, a composition, or other work of such kind. A thinker needs also to have something that lets the thoughts to be born. We just need to find out if the thoughts, or even a small part of them, is created out of nothingness, or if all of it is only recycled memories and sensations.

I think I have been controlled by external factors, Cat, more than thoughts.
I think sometimes thoughts do come in my head and I wonder if someone else put them there, from the other side.

Sometimes I create my thoughts and sometimes they seem to be placed there. Other times an answer to a quesion will pop into my mind and that's from memory.

I agree wit maria B and say both. some we make and some jus seem to appear there.