One of the amazing things about being a DBA/developer in 2016 is the sheer amount of freely available, downloadable data to play with. One fun publicly available data sets is the American Social Security Administration names data. It contains all names for which SSNs were issued for each year, with the number of occurrences (although names with <5 occurrences are not included to protect individual privacy).
A RAC DBA needs to keep at least two sets of environment variables handy: one for the Grid/ASM home, and one for the database home. Here's how I set up my .bashrc to make that easy.