I've looked after Charlie today, he is a joy to have and such good company.   My son dropped him off this morning and as we were having a cup of tea Charlie did his usual patrol of the garden but when he came back indoors I noticed he had a piece of fur missing on his forehead right between his eyes.   We don't know how he did it and spent some time checking for sharp edges and obstacles but couldn't find anything obvious.    He doesn't seem perturbed by it and is as happy as ever, as for me, I feel mortified that he's hurt himself in my garden.