Perhaps the key to happiness isn't about finding yourself. We try to make sense of the world by categorising ourselves into things we can do and can't do, and things we like and don't like. Since so much of that is dependent on the path we have taken, that can't be who we are. I think Megan is correct that choice can actually reduce happiness and effectiveness so perhaps accepting the path you are on is actually a good thing. The trick is realising that just because you are on it doesn't mean that is who you are. With a little effort, I think you can change bits and add bits.
One of the first questions I get asked when I talk about what I am doing is what is my five year plan? A contradictory but related line of questioning digs into why I feel the need to promote people trying to change themselves. Isn't constantly trying to push on to some better version of you half the reason people are continually beating themselves up? I suspect that the two 'competing' approaches are actually more closely connected. If you are happy with the current state of things but that state of things has an element of flow, then you can be both happy with how things are and happy that you are opening yourself up to awesome possibilities in the future. I will track down the source, but I heard an awesome suggestion that we shouldn't have huge life goals. We should break it down into lots of mini-goals. Lots of things that we can achieve and enjoy doing. This is like what Josh Waitzkin describes in creating smaller circles. Gretchen Rubin, of the Happiness Project, is a big pusher of the idea that we tend to overestimate what we can do in the short term, but underestimate what we can do in the long term by doing a little bit at at time. If flow is present, I think the longer term plan(s) take care of themselves.
It needn't be about wanting revolution. But introducing positive tweaks can mean you are both happy with now, and set you on track for an awesome later. Every now and then though, more than a tweak is needed. Brett points out something uncomfortable in 'Learning and Unlearning'. Even those of us who actively 'self define' ourselves as not racist, classist, sexist etc. are still human. We don't always want to be pushing ourselves outside our comfort zone. Our default once we are relatively happy is to carry on carrying on. I actually do think most of us are pretty happy. We like to moan, but when I dig most people in my circle are content. I think people are survivors and we move forward. We need a jolt sometimes though because of our biases. As Brett said, it isn't really good enough to always spend your time and energy with people like yourself.
Although we have a set of boxes we fit into, and an identity we have created. It is useful to realise that whatever that is, we are not that.