1st time building a helmet. It's an ATA helmet I've been worried about every little cut I make (remember your first time). I'm still working on getting the ears ground down, but have the face and back/top put together and just had to try putting it on my head. It seems small and I don't think I have an abnormally sized head. Is this normal? I'm sure I could trim it down a little more, but like I said, always worries about cutting too much. Roomie inside once it's on, the hole just seems small.