Obviously I come at this question from a heterosexual male point of view, so I'm mostly interested in that, but I'm a little curious about the female side of this too I suppose.
A couple of years ago I did some research on it and I came up with results pretty similar to what I found here: about 1.1 million people aged 25-44 are virgins and by age 19, 80% of men and 75% of women have lost their virginity. Now, I wasn't able to find the total number of adults aged 25-44, but if you use the demographic numbers from the US Census Bureau and play around a bit it's roughly 100 million adults give or take. So 1.1 million is about 1%.
Sorry about the math there. I know it's a lot of numbers to read all at once.
My main point is that most people by the time they hit 30 aren't virgins. And odds are if they aren't virgins they've probably kissed a girl, and had a girlfriend. So it's a far more useful indicator to use.
Now, people can lie on self-reporting surveys. People might be ashamed at the amount of sex they've had or not had and will lie or round their numbers to something they think might seem more "normal". So you have to be a bit suspicious about the numbers. But in my experience the numbers more or less jive with what I've seen in real life: I only know two people who remained kissless past the age of 21. And I know shy guys, religious guys, people from other parts of the world, people who smell, people who look weird, etc. I don't know about the virginity numbers because I don't know everyone's sex life and don't care to.
So given these numbers and given what I know about people in real life, and given that people often lie about these things, how many people do I think are kissless inexperienced guys past the age of 25? I think the number is somewhere between three and seven percent. And that mostly depends on who we're counting in the overall pool, and I'm actually leaning towards the lower end of that number.
Yet on message boards, websites and forums that I read and post on, there seems to be a feeling that the number of "forever alone" type guys has been steadily growing over the past 10-20 years. Most of the people who subscribe the this theory tend to blame women for being too picky, feminism and single mothers for teaching men to be passive, or society for valuing alpha males over beta and omega males, or some combination of these theories. I'm willing to believe that the percentage of older inexperienced men has grown over the past say 50 years, but not by any significant margin and not for the reasons given by these internet commentators.
I now bring it to you readers. How common is it to find a guy (or a gal) who has made it to age 25 or older who has not had his first kiss, has not had sex, and has not been in a relationship? Is my estimate of 3-7% too high, or too low, or just right? Am I missing some big increase in inexperienced guys? I thought this blog was unique?