Likewise. I achieve very little unless I feel like I'm letting down other people if I don't succeed. I can cope with the self-loathing of letting myself down, so if my plans are private I struggle with motivation. In fact, I add extra sticks (which I react to far better than carrots): two years ago I announced my weight loss goal – which had a strict deadline – in public and the extra stipulation that were I to fail, I would not touch alcohol for the entire following year. I firmly believe that without either of those, I would have found it ludicrously easy to cheat and fail.

Agree. It seems plausible that this just varies by personality: some people are motivated by announcing, some are demotivated (and probably some are indifferent).

That's gernerally true for polster-types who brag around with what they have done wjile others see their contribution rather miniscule.

I know this could be understood insulting, still my observation though.