Off topic kind of: When I meet a man over 35 or so that has never married nor had kids I raise an eyebrow...
Believe it or not, even though I'm dating a man who falls in this exact category (by a year), I sometimes raise an eyebrow.
I stress the word "sometimes" though.
Even the dude himself said that when someone is over 35 and never married, there's usually a reason. Not a BAD reason necessarily, but a reason.
If I'm beginning to date a man in this category, I listen very closely to see if I can figure out the reason. I am totally fine with a man who spent lots of time working on a career/business/school and found himself single because he didn't happen upon a mate like he might have thought. That happens to a lot of women too. However, I would look to see if he's NOW actively looking for one since he's realized that he's spent a lot of his adult life on a career or school.
If he is in the process of actively looking, then I don't hold the age against him at all.
On the other hand, there are some men in this group who gravitate to eternal bachelorhood. STAY AWAY FROM THESE DUDES!!!! I've run into them and realized eventually that they probably weren't going to marry anyone -- that they were set in their ways and their time to get hitched had passed in their minds, so to speak.
These types might be the old dude in the bar/club looking ridiculous, someone slightly asexual or simply lacking in social skills. There is research that says that if a man hits 38 not having been married or with no immediate wedding plans, the probability of him marrying falls significantly. I was ready to run after talking to a guy I met online (who was 39) who said he was tired of people asking him when he was going to get married and how he was "not in a rush."
Good for him, but that was a big sign to RUN for me!!!
Also geography plays a role. A 35-year-old never-married man in say, Alabama, would cause me to raise an eyebrow, but the same dude in NYC would not at all.
Not every single and childless man over 35 is the same, so it's good to at least see where their heads are about marriage and family if that's what you want.