Not generalizing, but for me personally, I'll often tell people about my plans as a way to hold myself to them. If I keep it to myself, it's easy for me to talk myself out of it, but once it's out there to other people and I know they're going to ask me for followup, I can commit.
I always think this way, but once I make a commitment, now I basically have a deadline, which for me, causes the procrastination impulse to kick in, and it takes effort to fight it.
I think that telling someone I'm going to do something makes me want to do it a little bit less because now I'm doing it for them, not for myself.
