'In my younger and more vulnerable years' is the opening to which 1920s book?

My vote for one of the best novels ever written is "A Gentleman in Moscow" by Amor Towles. Delightful, different, beautifully written. Finding happiness and fulfilment in the most difficult circumstances, plus a happy ending as befits such a book and there's some gentle humour as well. In this ugly present age, how did such a book come to be written?