Assuming you're not trolling (your first sentence gave me pause at first). I want this to be a surprising observation, because I consider following up on things

Assuming you're not trolling (your first sentence gave me pause at first). I want this to be a surprising observation, because I consider following up on things to be sort of second nature, but I've noticed how bad people are in general at following up on something they say they'd do. Even professionally, finding the people in an organization who will do what they say they'll do, and, more importantly, not agree to something that they won't, is a big key in getting projects pushed through larger departments. To add to this idea. I know someone who used to be very deeply embedded in an organization that has historically skirted the line of being a cult. Apparently one of the key tenets of this group is the importance of integrity, which they partly define as doing what you say you'll do. (From what I can tell, this is important for the organization, because then, they can set up environments where they can get you to agree to things then know that you'll follow through even if you come to your senses later.) What my friend noticed, is that people who moved on from this organization tended to be pretty successful in their careers, and they commonly attribute the ease of their success being that they simply do what they say they're going to do, and not in a woo-woo self-actualization sort of way. They simply do the types of simple tasks that others don't bother with, or forget about, like forward an article to someone who they said they would.