I'm not sure if I completely agree with this because you can be happy from being with other people, but I think I would agree more if this said positivity instead. Being happy is a very personal thing and it really has nothing to do with anyone else.
I really like this quote, but I don't think this would truly take just one day. You'll have to fight for much longer, survive for much longer, persevere for much longer. And the truth is some of us won't get there. The world is too unforgiving for that.