I was forty when I started and have been at it, on and off, for the last thirty years. Like others on this thread, I find the idea of a luscious twenty year old very arousing. But I wouldn't dream of going there and not just because at my age it wouldn't feel right. The best punts I've had have been with women aged between 35 and 45, give or take a year or two either side. This is because they can still be gorgeous to look at and, more important, because they've been around the block a few times and know exactly what to do to give you the best possible experience. If you go for someone like that, and provided she's got the right attitude (read the reviews, carefully), you'll have great value for money and the time of your life.