YOU may not agree with him, but it hardly matters. Ajeya Singh loves to describe himself as a country boy: "Thats what I am at heart. My secret desire is to esc-ape to the wild jungles." The world outside, however, knows him by many descriptions. One of which is incidentalcountry head, India, Lehman Brothers. Anotherof which he is quietly proudis being ranked among Euromoneys 50 global financial leaders of the 21st century.