Is this all there is? A chemical reaction? No magic like telepathy?

I think there is something approaching telepathy that comes after the chemical reaction. It's not magic, though, and a programmer like yourself might appreciate it.

The chemical reaction is what gets us to seek out the other person's company and feel a fondness for them. That proximity and care leads us to want to understand them.

I believe our brains create a literal simulation of our partner's mind that overtime converges towards their actual thought processes. In that way, we are feeling and thinking what they're feeling and thinking, and vice versa.