Hi everyone My brand new Retina MacBook Pro finally arrived yesterday. It's my first ever Mac and so far I'm really enjoying it. OS X is very nice and the screen is amazing. With all that said, I'm a little confused about the RAM usage. I've got the base model, so 8GB, which I thought would be plenty. I've currently got Safari (3 tabs), Mail and Messages open. Activity Monitor (also open, obviously!) is telling me that the system is using 7.5GB! Is this normal? I'm an experienced Windows user and would expect to have a lot more free based on what I've got open, but perhaps OS X works differently? I didn't bother spending the extra money to get the 16GB of RAM as I thought it would be overkill, and I'm a bit OCD and like to have power/memory to spare so this is bugging me! Am I just being over-paranoid or is something wrong? I'm running Yosemite of course and am fully up to date. Thanks!