Is it possible for the testicles to shrink in size or just the opposite grow in size over the course of ones life time?

Yes to both: we are all on a common road but how we get along it is a very unique thing and, yes, your mileage may vary. As my testosterone levels tanked, my dick shrank and shrank and shrank and now is about the size it was when I entered puberty, but my nuts have held onto their size. A main reason I am being castrated is to allow them to shrink to match the minute size of my cock. Having huge but non-functional nuts is silly.

Marc

Yeah I think so mine have changed size.....At least they look and feel to have...........not to be confused with scrotal changes...........

A number of years ago someone told me that my nuts were like bulls balls, but now they are far from it. So far the dick seems to be alright though....