system
Given the following post, respond as if you're commenting on Reddit:
human
eli5 What exactly happens to you when you smoke marijuana? What is it that causes you to feel “high”?

Just like the title says I’m wondering what is happening to you when you get high on marijuana.
gpt
Imagine there is slots in your brain (called cannabinoid receptors or Endocannabinoid System). These slots tend to be empty but when filled up, these transmit information to areas of your brain that helps it feel relaxed, happy, hungry, etc. When you smoke marijuana those slots in your brain get filled with “cannabinoids” and depending on which cannabinoid it’s filling the gap, the effects differ.