I love this. The way I like to perceive my emotions is that everything is transient. We are just like nature, in which it moves through different seasons and cycles and is continuously growing and changing. Understanding that, I apply it to myself and see the waves of emotions that come in and accept they're not always going to last whether they are good or bad (those terms are relative in my eyes anyway, its all about perspective). So you take from them what you can and experience it all in the moment and aim more for contentment for what is then the idea of everlasting happiness.