Dear Neil: Valentine’s Day just passed by. I didn’t think it would bother me that I’m not in a relationship, but it did. I spent the day with one of my grandchildren, but it did not erase my sadness. Last summer I went to a college reunion, and had many men flirting with me, but no one asked for my number. I occasionally see a man on a train who appears to like me, but he doesn’t ask for my number either. I do explore dating sites a little.

I recently heard my ex-sister-in-law has remarried. She was the world’s most cold and unlovable person. How can she be in a relationship and not me? Can you advise me?

Forlorn in Denver

Dear Forlorn: Part of the problem is that many people are in a committed relationship but not necessarily married, not wearing a ring and not actually available. Then there are those that will not find you attractive, or you’re not the right age for them, not the right body type or that you’re not the gender they are looking for.

And a large number of mature adults have simply quit looking for a romantic relationship at all. They have, in essence, given up the quest for romance, or have erectile dysfunction (and thus consider themselves out of contention), are preoccupied with work, children or family, or are otherwise no longer interested in pursuing an intimate relationship.

But there are plenty who are, and that’s where you need to concentrate. Getting more active with online dating sites may be one avenue to explore, such as trying different sites, posting more flattering photos of yourself or making your online profile more interesting or spicy. Also, quit waiting for men to contact you. Many men are shy and fearful of rejection, and would be flattered if a woman wrote saying she noticed his profile, found him attractive and would be interested in making contact with him. Increasing your assertiveness may serve you well on dating sites.

Also, frequently put yourself in situations with new people, by taking an adult education seminar, a parks and recreation hike, joining a chess club or signing up for a dance class, as examples. You are trying to increase your exposure and your visibility so you can meet as many people as you can—increasing your chances of meeting someone you hit it off with.

And perhaps the time has arrived for you to be a bit more bold and daring, and not wait for a man to ask for your number. On the train, for example, you could tell the man that he interests you. Is he available to explore a possible relationship? Taking that same attitude into chance encounters with new people may also help. Many men assume that a woman is taken, and they are therefore reluctant to try—assuming they’re going to be rejected.

Of course, if you do what I’m suggesting, it is you that could find yourself feeling rejected. It’s going to take patience, persistence, guile and luck, but a relationship for you is out there. Don’t let yourself get cynical or jaded—and then give up. Too many other people have taken that route. Hold yourself accountable to find the relationship you hope for.