It's not an unusual tendency for women to prefer men older than them, and men to prefer women younger than them. So these preferences can match up to a mutually preferable arrangement for both parties.
Also, FWIW, parent said "friend/dating" range. Which potentially means 20-35 may not fully apply to both categories.
This is veering wildly off topic but I'm curious: don't you think people in their early 20's would also be on a wildly "different clock"? I'm only slightly older than you are and through a weird series of event ended up frequenting a WhatsApp group populated mainly by people in their early 20s and the culture shock is pretty large.
People in their early 20's are generally students, they have different priorities, lower incomes, different cultural differences etc... It seems easier to find 40yo who share my interests and my lifestyle in my experience.
The "different clock" hombre_fatal is referring to is the "biological clock" - A single childless woman aged 35 who wants a family with two or three children has very little time to waste (assuming she wants a traditional two-biological-parent family structure which is extremely common among members of the upper middle class).
They need someone ready to make a lifetime commitment - and as it's rare to marry without dating for at least a year or so, they've only got a few rolls of the dice left.
If that's not where hombre_fatal is in his life, such women won't see a future with him.
Your clock as a guy actually isn't as different as you might think compared to women.
Yes, biologically speaking, having kids later in life is more doable for men than women. But you don't really want to put it off much. Kids require a lot of energy, and you want to be around for them growing up and moving out. And hopefully having their own children.
Don't be thinking you have all the time in the world!
Interesting.