Idea of space

How we could have the idea of abstract things like Love?
Emotions are complicated.

Speak slowly but continuously and clearly.
Things are invisible create a lot of trouble for the brain which wants to catch them like time, space.
I concern about metaphysics. Physical things are easy to see and to test.

Love belongs to metaphysics.
It is hard to talk about abstract terms that is what creates debates. No one debates about a bicycle but they will argue about a stimulus plan and benefits.