Why many of the unvaccinated insist on going without

I recently had the opportunity to hear a 95-year-old man speak on the subject of covid-19. When asked if he’d gotten the vaccine, he responded that he received it as soon as it was available. He went on to say that, in his long life, he has seen this behavior over and over again with regard to vaccines. He has lived through the people who were smarter than the measles vaccine and the mumps vaccine, smallpox, polio; there has always been a percentage of the population that refused them.