Help With Grab Brush In Sculpt Mode I want to do something similar to this

https://youtu.be/R-I2l1G8CaI?t=2m17s

I'm trying to grab the back of the "head" but what I get is something like this



My sculpt is mirrored along the x-axis and so is the one in the YouTube video. But when I try to grab the back of the head, it looks like a butt while that in the video does not. Please help.
As i gathered from the comments, your question has already been answered. For future readers:- Uncheck "Front faces only" in the brush tool settings