Buy yourself a pretty journal... and a nice pen - one that you enjoy writing with (gel pens are kinda neat!)...
Trust me... years from now you'll look back and be amazed at how far you've come... and what is quite amazing is that you'll likely learn that what makes you who you are today (your basic beliefs and values) will still be there. Its helpful to gauge your personal development/changes... always be true to who you are. I sometimes use a different coloured pen and update my thoughts a couple of years later.. depending on the circumstances.
Sometimes I think... what if someone find this... then I figure... oh well.... I'm doing it for me... not them... so if it doesn't make sense, then who cares!
Anyway... out you go to buy that special book.... tell me about it

Addy