Are you always looking for more information on Exadata or 12c? How about learning from an Oracle instructor on these subjects? If you answered yes to these, then you NEED to visit Martin Bach's blog! The best part of this is how much Martin references and links to documentation from a variety of different people on these subjects so you can read his blog and get involved with others in the community to learn even more as time goes on.
Bonus: I enjoyed the post here about wait events that are being introduced with new versions of the database, and makes me think about creating some documentation for myself to keep track of the "new" ones I encounter in the wild and those I am looking for!