If you have ears to listen, then almost immediately after meeting anyone, they will explicitly tell you what joy they can bring to your life.
Everyone has something. Everyone has a particular kind of happiness they can give you. Our great task is to accept that joy from everyone, no matter the person, and to not expect any other kind. Almost all of our sadness about other people comes from expecting something from them that they never offered, and in fact are not capable of giving.
No one can be everything. You can’t expect everything from anyone, therefore. You have to take people as they are. If you can, if you do – they are joyous. They are wonderful, in their way, each one of them. You only bring them low with your own inflated expectations.