Okay so obviously you don't have to, and I know what you're thinking. No. Just plain and simple, no. And to be honest, I get it. Keeping a diary, or a journal or a scrap book or even just holding on to old tickets and flyers can be arduous and probably isn't for everyone... But for those who it is for, and those who make the effort to do so, it is so incredibly rewarding.
Along the way on our 13 month trip in 2014/15 Sean and I kept a diary AND a scrap book. In the diary we drew little pictures and scribbled a few words each day about what we did, whilst in the scrap book we collected tickets, wrist bands, business cards, flyers, flowers and more. And I'm not going to lie, both items took a lot of time and dedication to continue adding to throughout our trip, but boy oh boy is it worth it now.