At a time when it is hard to get people to agree on barely anything, here’s a truism we can all sign up to: good manners cost nothing. You may think courtesy is over-rated, or unnecessary in a digital age, but I’m sure you can accept that there is no financial implication to saying “please” and “thank you”. Gordon Ramsay is with me on this – he has six kids and says teaching them manners is the thing he’s most proud of as a parent. I assumed tha…