2004, it lasted almost 10 years? I've never had a helmet last that long since the first Bell Biker helmet that was made, that one lasted me 10 years before getting destroyed smashing a car window out (actually the shell held up the styrofoam did not). Since then they haven't lasted as long. I think the more a person rides the more frequently the helmet needs to be replaced. I also think that since I lived in So. Calif the foam degraded faster due to heat, UV, sweat, and ozone. Since I've moved to Indiana the foam hasn't degraded but the liner has, was this a change in construction of the helmet or a change in the environment? And perhaps body chemistry plays a role too, I may have a chemistry that makes helmets die faster. I don't use any chemicals on my body for sun, bug, or hair color or protection, so those are not factors for me anyways.