A good friend leaves you with more of yourself, not less.

You can tell a lot by what is left of you after an evening with somebody. With some people you come home with more: an idea you want to try, a thing you said out loud for the first time, energy for tomorrow. With others you come home smaller, careful, replaying what you said. Neither has much to do with how fun the night looked.

Run that check on the people you see most. Not are they nice, but what do I have more of afterward. Spend your good hours on the ones who leave you fuller, and let the rest become people you see occasionally.