This is the first of Dornford Yates's "memoirs," written when the Second World War was over and the privileged society he described in the "Berry" books had disappeared for good.
Part of the problem with "As Berry and I Were Saying" is precisely that it is cast in the fictitious world of Berry rather than that of the real-life author. This is not unexpected, as the life of C.W. Mercer ("Dornford Yates") resembled not at all that of the Pleydell family as depicted in the "Berry" books, and indeed there is something sinister about Mercer's cloaking of his strictly middle-class identity in the persona of Boy Pleydell.
In the book, Yates turns out to have been a bystander in some of the more well known incidents of the early twentieth century (the Crippen case, the suffragette demonstrations). Berry himself contributes "monographs" on subjects such as Napoleon brandy or the awfulness of the Germans. But the book as a whole is a lament for the good old days when a British gentleman could travel overseas without a passport and the peasantry touched their forelocks to their betters. If you yearn for those days too, you might enjoy the book. If you are more interested in Dornford Yates's peculiar psyche, see if you can track down the rare biography; it is definitely out of print and currently unavailable used on Amazon, but it will tell you more about Mercer/Yates than this memoir or its sequel, "B-Berry and I Look Back."