That hits on what I think is the must have for intimacy... mutual trust. Some people only see relationships as transactional. They're "acts of love" are merely a means of getting what they want. And, sadly, they can only see their partner's acts from that perspective as well. They cannot trust and therefore cannot be truly intimate. In your case, Dan, you trust that your wife made that salad primarily out of her love for you. I say primarily because being a bit selfish sometimes is human nature and normal in any relationship.