Hi and welcome! I love this topic and have a question. You said:

"This finding led scientists to believe that if we have such receptors it is most likely because our body produces substances that are similar to cannabinoids (called endocannabinoids)."

what triggers humans produce endocannanbinoids?
Is that speculation or fact?

What other functions does the endocannabinoid system have, other than giving humans ability to receive cannabinoids, if any?