So my computer was feeling sluggish (clicking on something in firefox was taking to much time to respond) so I was looking into my memory usage, and saw that 85% of my 16GB of memory was being used... so I closed a bunch of stuff - and rebooted and came back to an empty desktop - and did my memory test again (CLI: ps aux | awk '{print $6/1024 " MB\t\t" $11}' | sort -n) and got 967.641 MB /usr/lib/xorg/Xorg and thought that seems like a really high number (when I remember before Ubuntu Mate taking up around 650MB total on a fresh reboot) - so I'm looking for ideas as to what is happening and how to go about fixing this???