//...but I think we should follow guidance whilst using common sense//
Alas you cannot do both, f-f. Much of the guidance has no foundation either in science or common sense. The area I live in has a very low rate of infection. The neighbouring area has, for some reason, a considerably higher rate (though still incredibly low, as are most areas in the UK). I am planning to go on holiday next month. Where I am travelling to has an infection rate much lower than where I live (about a quarter, in fact) and considerably lower than my neighbouring area. I can travel to my neighbouring area as often as I like. I can (and do) shop there, go for a meal there, go to a pub there and return home as normal. However, if I go to my chosen place for a holiday I have to quarantine when I return "to avoid spreading Coronavirus." I have five or six times the chance of doing that when I go for a meal a few miles away than when I go on holiday but I am allowed to travel there without restrictions. My common sense would tell me to be far more wary when visiting my neighbouring area than when I go abroad. But I'm not allowed to exercise my common sense.
So it is with the "rule of six". I can mix with five different people in a pub. I can leave the pub and mix with five other people in a nearby restaurant. The five I have left can each do likewise and the thirty of us can all eat in the same place. But I cannot meet more than five of them at one table. It is ridiculous, it is arbitrary and has no basis whatsoever, let alone be founded in common sense.