Nowhere near as profound, and I thank your father for his service, and give you my condolences, my grandmother had dementia before her passing and it is an incredibly cruel thing.
My interest in sub games first came about through the NES game Silent Service which I borrowed from a friend in Primary school. After that it lay dormant for some time before watching Hunt for Red October and reading and re-reading a book on submarines that my Uncle got for me when I was about seven or so. Following that I got Fast Attack for the PC when I was about fourteen or fifteen, then went on to Sub Command and that was that really.