I'm lost. What's my purpose in life?

I have a personal mission statement and constitution. I try to review it at least once a week to revise it and reflect on how well I've lived it the last week, and to plan on how I'll better live it.  In my constitution I have principles and values written out, such as "I will have fun at failing," and "I will not judge other people." Sometimes I succeed, sometimes it's like I've forgotten this list exists. What is perhaps more important than the constitution is the mission statement. I have not been very happy with the life purpose I've defined for myself. It's vague but it's the best one I've come up with. The only thing I'm really happy with is that I deliberately chose a purpose that I thought most other people wouldn't understand on any level (I'm weird- I embrace it). I'm told that reflecting on my life purpose should bring me to tears. That you can find your life purpose by sitting down and writing hundreds of "life purpose" statements until you find the one that makes you cry. I've tried that, but nothing gives me that emotional "umph." And I've been worried that I can't find it.

Sometimes I think, hey I just need to focus. #1 Work on finding a proper life goal everyday. #2 Have some flexible plan for advancing that life goal each and every day. #3 Make sure by the end of each day I've met some milestone and feel like I've made progress. Then things will work out.

Not only is this focus hard, I'm also not sure it's the best plan anymore. I've been worried that I don't have a satisfying life purpose, but I think now that the worrying is the real problem. It's occupying me with trying to find some "ideal" life path and so I feel like I don't have enough time to experiment with new things. 

Society teaches us to focus on the career progression (in science it's undergrad => grad student => post-doc => junior faculty => tenure), or the life progression significant other => married => family => house in suburbs. If you don't make progress, others are trained to ask you why you haven't. Some people are happy with it, but a lot of people aren't. Some people think it's necessary, and they don't want to wander off it because it's risky. But you know what? I think a lot of it has to do with life/career progressions being pre-defined for you.  If you find your own reason to get married and buy a house that you won't pay off for 10 years, a reason that is made for you and only you, you'll be a lot happier with it.

This pre-defined path through life can sometimes feel like a prison. So we rebel against it, and we often go overboard and rebel in unhealthy ways. People party a lot, do drugs, cheat on their significant others, quit their jobs without a plan. Most of the time people do this to a lesser extreme, where we might simply lose focus on our work and do our own thing for a while. We might grow in new ways, but then reality sets in and your boss yells at you and you realize your peers have published 3 papers while you have nothing to show. So you freak out and go back to the pre-defined path. You feel bad. Nothing you feel bad about can ever be maintained (omg I HAVE to do this or else my career tanks). So it starts to fail. You work long hours but your work doesn't go anywhere, and it's because you feel bad about it. It's a hell-on-earth prison. So you rebel against it, and it starts all over again.

These are meanderings. We have to deal with societal expectations, but we also have to find our own way. Finding a correct balance- no, the correct MIX of the two is critical. And what's the best way to address something that is critical? Find a way to make it fun. Then you'll do it each and every day, and you won't worry about it.

I recently served on a panel to discuss graduate and medical school with a group of high schoolers applying to college. Every other question was along the lines of "What should I be doing right now to make sure I get into medical school?" It didn't bother me so much that they already "knew" what they wanted to do right out of high school- sure, it's naive, but I have confidence that they'll properly re-evaluate once they are exposed to more life choices during college. What did bother me was that they thought they would be trapped in whatever career path they chose, so they were scared to death that if they didn't optimize everything in their education that they would be stuck in some unhappy mediocre position. That they had to choose their career path NOW so that they could do everything right in the pre-defined life progression. Society is pushing students to imagine some ideal path through life, and if you just follow that you'll be all set for life. I was sucked into this for way too long, until I really started to reflect on what I wanted to get out of life.

Over the past year, I've been focusing on internalizing the mantra "Don't think life is good vs. life is bad. Think about what you can do right now to make it better, regardless of whether it's subjectively good or bad." It's self-managing your own thoughts. But I've really only been applying it to the "what" and the "how" of life. Not the "why" quite yet, and I realized this month that this has been a constant source of distress that I haven't been able to really address until recently.

My goal now is to be lost. And I'm going to have a ton of fun doing it.

Last-minute edit: Yesterday I found a life purpose statement that brings me to tears. But that just moves the bar up, and I bet tomorrow I will subjectively feel just as lost. Finally, this post was motivated by the first question in this Q&A by James Altucher. I have found his blog to one of the most thought-provoking ones out there, even if I don't agree with him. And his honesty is an inspiration to anyone who feels like they have hide their failures to prevent society from judging them- which is everyone.