> Also when you say yes to people, a lot of time the other person never actually follows through the thing you didn't want. Otoh if you would argue or say No beforehand it always has the opposite effect.
I recently started doing this and it's amazing. I was the one saying 'no' to so many 'offers' (as a full stack developer, from idea people), and always ended up being the negative guy that doesn't want to do things.
Recently I've started enthousiastically saying "Yeah, that sounds great! In order to get started, I'd need <whatever_thing_that_they_need_to_do> from you.". Up till now no one has followed up. When we talk about it next, I am as excited as in the beginning and mentioned the thing that they need to do again, and they usually go like "Oh yeah! I need to do that." and then I never hear about it again. It's a shocker to me.