I thought I knew better also, some of my hobbies and habits at work contributed to severe hearing loss. Tons of machining time, long loud cuts, grinding, polishing, gouging, shooting skeet for hours. Me and my wife are both 3/4 deaf, I lost a lot in the higher frequencies from the triple cylinder snowmobiles I had that were equipped with race pipes and no silencers and spun 10-11k rpm. Chainsaws, dirt bikes, race quads/trikes, tractors skidders, heavy equipment, Nitro RC stuff. I don't know how many small engines I tinkered with but its a insane number, I work way too much. I try not to let the next generation make those mistakes I made and I get angry with them when I see them not wearing glasses, ear protection or when they do something unsafe. I have seen a lot of accidents over the years and I am sure you have also. Hindsight is always 20/20.