If you are over 18, your experience will revert to the one you're accustomed to. However, your social permissions with respect to community members under 18 will change. For example, if you do a member search, your results will return only community members who are over 18. Also, since community members who are under 18 will no longer be able to participate in regions or forums, some people who you are accustomed to seeing may disappear from those spaces.