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Sam Trenholme’s blog

Happy birthday, Marina

November 30, 2025

I wish my departed wife a happy birthday, and talk about the 80/​20 myth and whether it applies to young people.

In memory of Marina Rojas Nuñez

Marina Rojas Nuñez, 1974-2024. Today would had been her birthday.

My departed (and probably first) wife, who passed away on September 12, 2014, would had celebrated her birthday today. She was a very beautiful women, and I’m glad we got to spend the happiest six years of her life together.

Her daughter—our daughter—is doing really well and I’m glad to have her in my life today. I am dating again and moving on, but I will always honor Marina’s memory.

Famous people who share a birthday today with Marina include Mark Twain (Samuel Clemens) and Winston Churchill.

I wrote extensively about Marina in a previous blog.

80/​20 and 18-29 year olds

NSFG 2022 data including data for just youth aged 18-29. The black line highlights the percentage of male and female partners the “top” 20% have.

This continues my discussion of the 80/​20 myth.

The 80/​20 myth is a myth that 80% of the women sleep with only 20% of the men. I have shown it to be a myth; this is in response to a question whether it is true for only younger people.

I have run the stats on just 18-29 year olds and the numbers are not that different than they are for all ages.

If anything, the trend of there being more virgins of both genders as well as the most promiscuous people being even more promiscuous continues: While the “top” 20% of men have more partners compared to all ages, the “top” 20% of women also have more partners.

In more detail:

• 20.66% of men (18-29) have 75.7% of lifetime female sex partners

• 19.96% of women (18-29) have 68.0% of lifetime male sex partners

• Virginity rates for 18-29 year olds: 30% men, 25% women

• 19.45% of men (all ages) have 71.5% of lifetime female sex partners

• 19.49% of women (all ages) have 64.8% of lifetime male sex partners

• Virginity rates for all ages: 22% men, 18% women

Note that:

• The most promiscuous people have even more sex partners, for both men and women

• In particular, the difference between all ages and 18-29 is that the “top” 20% have 3-4% more of the lifetime partner count, again for both men and women

• Virginity rates are about 8% higher with younger people, once again for both men and women

I discuss in depth the 80/​20 myth on a page dedicated to this topic.