At any age it is a considerable accomplishment to go from the germ of an idea for a book to the completion of the project.  When that achievement involves not merely the writing of the text, but the producing of the graphics in a work that is graphically top-heavy, finding a suitable printing company that can also offer help on the production and marketing side, and then taking total responsibility for the financing, publishing and distribution, this is an achievement of which anyone, at any age, can be justifiably proud.  Let alone someone in their mid-eighties.