So my 13 in. 2011 MacBook Pro with Mac OS X Lion 10.7.5 seems to always have a large amount of data to backup when I use Time Machine with a 2 TB WD Elements external hard drive. For the past few times I have backed up my Mac, it has about 80-90 GB of data to back up, although I did not remember getting that amount of GB inbetween backups. I have about 180 GB of Audio, 151 GB of Movies, 22 GB of Photos, 17 GB of Apps, and 146 GB of Other, with about 235 GB free of 750 GB on my MacBook. My external hard drive is filled with 939 GB of Backups, and free with about 1.06 TB. Please help!!! It's driving me crazy, and I'm scared that I will somehow max out my memory on my Mac or my external hard drive. Thanks in advance to anybody that answers me!