Because it's trying to tell you you're doing things wrong (need to be more careful lifting!)
Why didn't I check the manufacturing date on my new helmet BEFORE I bought it? I checked it after and discovered why it was $200 cheaper than the normal price (of $300!!! Ouch, show helmets are too expensive hahaha)... it will be 5 years old in February, meaning I should replace it as helmets are supposed to be replaced after every fall where you hit your head, or 5 years past manufacturing date, whatever comes first.
A CLEAN SLATE FOR THE FUTURE