For years now, there have been research papers indicating exposure to blasts in the military can cause permanent and observable changes in brain tissue, resulting in cognitive changes. Blasts can be IED’s (home-made bombs), artillery or anything with an explosive charge including 'breacher' training to gain access to buildings.

Our brain is not immune to changes with time and what I will call significant life experience (read getting wiser and older). The positives of getting older are of course wisdom, knowledge, better emotional regulation skills and maturity.