Well, some of us need the repetition, dear.
(i.e. me!)
Yes, i agree it is no one else's responsibility to bring us happiness. And yet today at the same time i am appreciating how much people affect my happiness and mental health. Today i have a house guest... what a difference it makes in my life! I am happier and more focused when i am around other people... so long as they are reasonably positive/healthy people.
I have also learned how much being around negativity (mostly criticism, pessimism, and anger) affect me adversely, and of course, abuse... even in minute quantities and even when not directed at me. I have learned as i get older to more consciously choose the people i allow to be close and involved in my life. I don't avoid negativity entirely... almost everyone has times when they are sad or angry and i don't chuck friends just because they go through a rough time... but i don't keep people who are regularly like that in my circle of friends. I'll suggest to them it is poisonous, but if they don't get on board then i let them go.
But people in general... are good for me. Most of the people reading this have family or people they live with. I don't, and my family never paid me much attention. They are not, for instance, people who will call me on any holiday. So i notice quite a bit of difference when there are people around and when there aren't.