BADGES!
Nerds are enthusiastic about things, and wanna tell other people about what they love.
Badges are a way to share the things you love, the new things you are trying, and the things at which you are kind of an expert.
There are badges for Culture (things you consume: books, TV shows, poetry…)
and badges for Skills (abilities you acquire: juggling, origami, cooking with eggs…)
And for each badge you can earn the badge at 3 different levels:
Novice – you tried it, for a good solid try, and you may not LOVE it, or maybe you do, but you are familiar with it, understand its challenges, and for those that like it, you can see what they are talking about.
Veteran – You really like this, kinda love this. You finished veteran and kept going, achieving a certain high level of consumption or skill.
Legend – You are a downright impressive in your investment in this badge, if you do say so yourself.