Well, he says it fits better than new ones he has tried on. Still, don’t know how many that has been and if they were different shapes to begin with.
Nktilva, in case you don’t know yet there many different head shapes ranging from long to oval and different helmet manufacturers make the helmet shells in different basic shapes. That’s why it’s important to try on different brands to see which one really fits you. There was a definite ahah moment when I tried on my Arai Profile (note that Arai make helmets in different shell shapes).
I think I saw somewhere that it is the sweat from our heads that eventually breaks down the EPS layer. If the helmet has been sitting on a shelf for 6 years then it might be as good as brand new. Not an expert on these things to this advice is worth what you paid for it.