Is reality in reality only thoughts?

I heard many times from different sources the affirmation that everything that there is are thoughts. Old philosophic ideologies such as Buddhists say the mind is all there is. Many alternative new age authors have stated the same, such as Deepak Chopra saying that the only difference between our thoughts and the universe as thoughts is that our thoughts are usually linguistically articulated. Others, Skooby for instance, have their personal experiences and thoughts on what it is all about and arrived to the same conclusion. I personally have considered this many times and I still have more questions than answers in this regard.

For instance, what is the source of all thoughts? who is the thinker behind the thoughts? (very zen question ;) what's the relationship between the thoughts and the physical brain? If we don't need a brain to think thoughts what is the brain for? If we do need a brain to think thoughts, nothing existed before brains evolved? (contradiction right there ...)

I can bring more questions, but hope to get some answers to these before.