That’s pretty much it, yup. Think about it this way, if you can feel rhe blast it moved some of your cells. If you feel the blast right through you it moved, and possibly damaged, cells right through you, including in your brain. As we’re learning from TBIs in sport, sometimes just one hit is enough to do permenant damage. From other sources I’ve read, it does seem to take a lot of blasts, but no one’s actually sure as it hasn’t been studied properly.