If you want to understand your thoughts, the best approach is to add a dimension.

For example: Time per day. How much time per day do I spend thinking one specific thought?

Or Quantity. Of all the thoughts I have, how many are pleasant and how many are not? Does that matter? Does it matter if my head is filled only with negative news?

Or Speed: do my thoughts follow one another rapidly, or slowly? That varies per thought and depends on the pace at which you live.

What I would never do is Buddhism. By adding "ego" as a dimension, you only cause yourself confusion; it’s of no use to you. And besides, the ego has to be removed later anyway.