You state right off that basically you don't have to work, you collect a pension.  So that automatically tells me that you are on the defensive, or that you don't need the money and you're not asking for a job as that's beneath you for all the years you worked elsewhere and by the way you don't need the money.  You see where I'm going?

State simply that you are interested in learning something new and have the energy to learn and take direction well.  State a couple of interesting positive points you researched/learned about the company and its product or mission statement that you are applying to and why this is the reason you want to work for a company like theirs. 

If you don't show your hunger and enthusiasm and eagerness to learn, you will be deemed "overqualified" which can also translate to someone who doesn't want to really work because they don't really need the money.  I hate to say it, but I've met "semi-retired" folk who had major attitude about taking direction from someone younger than them and complained about learning anything new, refusing to do what was expected of them and would just gossip/socialize.  A lot of employers won't hire simply because how would one work harder when they already have a check coming as opposed to the one who is actually relying on their one check?

Interestingly, the other end of that spectrum is the older supervisor who has always worked hard, never coasted on their seniority, and has to deal with young uppitys who want automatic respect but never worked a day in their life.  *nods*