The rational behind needing to register and login to view all of the entries on my blog are laid out an entry found here (which you should be able to view without being logged in).
Essentially it is to stop stop search engines and complete strangers from reading my blog (which is intended for my friends and family, and which others may misunderstand or misinterpret).
If you don’t want to register you will still be able to view many of my blog entries, but there will be some that you won’t be able to see without loging in.
To log in you need to provide an email address you can check and a nickname (which can be anything). Your password is randomly generated and emailed to you. You can change it to something easier to remember once you login.
Initially after you register you will still have the same access rights as a complete stranger, but the blog program emails me to notify me of new registrations, and will change access rights etc as soon as I can after receiving these notifications.