Yeah, and your head should rest up on it, hence the name and all that. It is there for that rear-ended collision. If you are leaned way forward, now it’s just something for you to hit, but if you are headresting, it’ll absorb some of the impact and prevent (or reduce) that cervical spine injury. Anytime I’m at a stop, especially in traffic, I try to remind myself to put my head back, just in case. It’ll be the time I forget that I get rear-ended though.