From her most recent Pitchfork interview, Apple says:
I'm not religious or anything, but now when I'm sad, I do a lot of kneeling on the ground and thanking whatever. Just for me, to acknowledge something and and make it physical so that it sets in. The thing I will say always is, "Thank you for my problems and I send my love everywhere." I am generalizing-- there are problems that just fuckin' suck and are terrible-- but problems like being sad or having your heart broken aren't any less valuable than happiness is. So when things are really bad, nowadays I recognize the value in it because I know it is going to make me appreciate happiness in the future way more.
I love the idea of saying, "Thank you for my problems and I send my love everywhere." This sounds like a great way to start the day. Apple's recognition of value in the "bad" in life so she may appreciate happiness reminds me of the yogic yama, Aparigraha. This yama means non-possessiveness/non-attachment. Just like with material possessions, we simply cannot become attached to our feelings. Our emotions are constantly changing. We need to accept this, and work to not attach ourselves to the feeling of "happiness", or conversely "sadness." Obviously, it's great to feel happy, but if we didn't have sadness, would we really appreciate the good times? Probably not. There's a wonderful quote from Kahlil Gibran about this that says, "The deeper that sorrow carves into your being, the more joy you can contain." Again, the idea that we should appreciate all emotions--good or bad.
It's incredibly difficult to practice this non-attachment, but the times that I have been able to do it, it has made dealing with things a hell of a lot easier. Releasing control is so freeing.