When they no longer appreciate your presence and write you off their lives, take a step back and leave them alone.
I must have missed the lesson where they tell you that ‘friendship’ sometimes means ‘abandonment’
"When all by myself, I can think of all kinds of clever remarks, quick comebacks to what no one said, and flashes of witty sociability with nobody. But all of this vanishes when I face someone in the flesh: I lose my intelligence, I can no longer speak, and after half an hour I just feel tired. Talking to people makes me feel like sleeping."