This study says that there is a link between waiting until you are in your 20s to have sex and experiencing sexual dysfunction later in life. That is to say, if you're not doing it now, you won't be doing it when you get older, either. Okay, well, not exactly. As this article highlights, correlation is not necessarily causality, but the things that link not doing it now to not doing it later are pretty interesting. Some suggest that in men, sexual dysfunction that starts when a man is young could cause him delay starting to have sex, as well as cause problems when he is older. There is also a link between feelings of shame and guilt regarding sex that keep people from having sex when they are young that can also cause dysfunction later on.
While those who get it on early on are not necessarily better off (they are more likely to get STDs, for instance), it does call into question whether the abstinence-only, demonization-of-sex-before-marriage approach is really a healthier view of sexual relationships than the alternative.