Choosing companions: who and why?

As human beings, how do we choose who we want to spend our time with?

This thought occurred to me the other day when I was patting my favourite street cat.

Why is she my favourite street cat?

1. She is the most beautiful (visually)? Maybe.
2. She is the cutest? She was when she was younger, but not now.
3. She is the most playful? No.
4. She is the kindest? Maybe.
5. She has the best colours? No.
6. She has the best pattern on her coat? No.

And so the list goes on.

What's the answer?

She is the one who reacts the most when I give her attention i.e. she gives me the most love back.....