Hey, WhodaThunkit. You have a lot of nerve bringing up sticky issues like this to a bunch-a-lazy early retirees.
I think this is a legitimate point. But I do have to ask myself, "Realistically, what are the chances that continuing to work with my electrical engineering and management background, I would produce something of great value to mankind?" I was pretty good at what I did, but I was certainly not in the same league as Salk or Einstein or Darwin or . . . I think my life is more likely to have an impact on a personal level than through some discovery or accomplishment that affects the world.
On the personal level, a lot of people who worked with me might have wished I had stuck around, but a lot of friends and family are probably glad I got out. And I really am happy I got out.
I guess you could look at your life at a level in between the two. I probably did some good for a couple of corporations (and indirectly, their stockholders). But it would seem really shallow to me to actually weigh that impact more than the personal impact.