It's all part of the learning curve Noggy, and it sounds to me like you're taking it all in. I find that when I'm in a good safe riding mode, there are very few people who leave as great a gap as I do between themselves and the vehicle in front, yet I doubt I'm beyond the recommended braking distances. Yes, others will try to take the piss to fill the gap you leave, but then you just drop back from them too.
One thing that gets me to slow down and just generally ride a lot more safely is my little mantra: there'll always be another time - typically applied when there is slow traffic in front on my favourite roads. But, on my planet we're very similar to you humans, not infallible, and there are times when we do silly things. We just try to minimise the risks when we can. There are times and places for spirited riding, and that's one reason I get as much riding time in as I can, create more of those times, in the right (or "more right") places.
Then again, on my planet, we can be very weird...