Siebe wrote: “I do not really understand this Lal. If a human being, if we, are nothing more than an ever changing composition of rupa, vedana, sanna, sankhara and vinnana (which i do not belief)..”
Can you explain what else is there in a human being or any other living being?
All living beings, except beings in the asañña realm (who have only the rupa aggregate), have those five “kāya” or aggregates, and nothing else.
It is easy to see this point by just looking at the rupa aggregate. When a human is reborn a brahma, that brahma will have a very fine body, very different from the human body. If reborn as an animal, it will be the body of that animal. So, there is nothing to be proud about one’s own physical body, and it will not last long either (100 years is negligible in the sansaric time scale).
– (Of course, one’s own body is only a tiny part of the rupa aggregate, it is called ajjhatta kāya).
This is the key to understand what is meant by Sakkāya Ditthi.