Many of us believe that the quality of older (unopened) bottles of many Spirits and Liquers are superior to their modern day counterparts. Whilst it is a fact that Spirits (and many Liqueurs) once bottled are basically inert there is a good reason for their superiority. Simply put, it is the processes and quality of ingredients being used 50, 40, 30 years ago that make them better.
Virtually no mass production, no modified ingredients, many less additives and a longer time in the production cycle are all part of it. I am not saying that everything old is better but it is extraordinary how different they can taste. I would humbly suggest that you find out for yourself!