Sounds like you are talking about things in your profile. Some of them, like choices to show/hide avatars and signatures, are in your profile under edit account details. You won't have a choice to change the threads or posts per page. We have a choice between BBC code and Rich Test for our...
In my limited experience, it's been more a seasonal than an age thing. Mine have mostly gone broody in spring, or late winter, with some going broody in the summer. I had one go broody after laying for only a month or two, and another who laid for two years before she ever went broody.