The pattern of thought that these lessons have generated seem to be frantic attempts at changing oneself with breaks where one tries to convince oneself that they have self-worth.
They coincide with each other in the context usually given. In order to be happy, you have to pursue who you want to be. Once you are who you wish you were, you will be happy.
The entire idea is flawed and is a utopian pipe dream. You can never be who you want to be. You can try, you can get close, but human nature is not to settle at the first checkpoint. You won't ever feel like you've done enough. Besides that, life and the world push our path through time all over the damn place and there is no possible way to plan to be who you want to be, and more often than not, circumstances will require you to be someone you do not want to be.
The way this is taught and propagated today is fine for children with a lot of guidance and realism. Schools can tell kids they can all be astronauts, but somebody needs to check them and explain the rest of what it means to have a dream and why you can't go through life expecting it to be handed to you. There needs to be a heavy emphasis on doing what needs to be done, and finding happiness in places other than work.
When it comes to "becoming who you want to be!" physically, any notion that it is an option should be outright rejected and it should be taught that any form of voluntary, unnecessary surgical or medical body modification are only desired by untreated mentally ill people. No normal fucking person gets plastic surgery for vanity. No normal woman sees breast enlargements and thinks it's a wonderful idea: something isn't right upstairs for you to do that shit. Hardcore self-acceptance is the way to go no matter what. That's how you expose strength, not by telling them there's a specific way to think about everything.
On that note, the purely isolated and distilled notion of celebrating oneself is a positive one. I live with a thought nested in the back of my mind: when I die, the last person I will face is myself. If I don't feel that I am someone I can celebrate, I'm fucked. My last hurrah is going to be telling myself to fuck off if I don't find ways to celebrate and love myself and the things I'm capable of. It's healthy and in fact conflicts with the other statement of being who you want to be. That insinuates that you are currently someone you do not want to be, and therefore you will reject yourself. I had to stop treating myself like that. It's like hanging out with a fairweather friend inside my own head. You know, that one friend that you always invite to the outings, and he's a dick and everyone points it out to you and most of the time you'd agree, but every now and then you pity the guy and you just think well he paid for drinks that one time... That's what it means to try to celebrate yourself while also trying to become someone else.
Celebrate yourself, have realistic goals, have a dream that makes realistic sense, but never run around believing that you'll get to be who you want to be. You won't. Learn that you will change through time and you need to find solid grounding within yourself instead of constantly trying to fight who the world has made you.