Reading through this thread there area few references to doing 80mph or more - not only is it illegal but it's illegal for a reason. Read this https://www.gov.uk/speed-limits and the link to penalties.
Regarding comments about people who drive slowly, as far as you driving behind them are concerned, they are doing it for a reason, respect that and consider it a 'road condition'. Stay well back and wait the opportunity to overtake sensibly. Believe me it is not worth taking a risk for the sake of a few seconds arriving at the end of you journey.
If you think that if you are innocent of causing and accident if you are doing 50 in a 30 limit and you hit someone who steps out then God help you. Idiots who break the speed limit are guilty by definition.
Roads nowadays are far to crowded. I feel sorry for new drivers because the Golden Age of Fun Driving on Public Roads is over. There are to many overpowered cars driven by people who think they can drive as fast as they like and are unwittingly relying on the good driving of sensible drivers.
And one other thing - you don't start 'learning to drive' until you pass your test.