He has been very unlucky up until this point

In this case, every woman that he has ever met, that he has really liked already had a boyfriend or a husband.
He has really bad luck when it comes to finding single attractive women.  Yet, he can change that. 

Lately, he hasn't been meeting many new, single women that he finds attractive

Imagine this… A guy wants to be able to get himself a girlfriend. He works in an office and he goes to work on Monday to Friday. On Friday nights, he sometimes goes for after-work drinks with coworkers and he usually just sticks within his group or talks to his coworkers.
He doesn't really venture out to talk to other women at the bar. Then on the weekends, he may sometimes catch up with his friends who already have a girlfriend and he may not like any of the remaining single women in his social circle. They may not be attractive to him. He may like his friend's girlfriend, or he may like a girl at work and find her very attractive, but she's already engaged, got a boyfriend or is married. So, as he goes through that cycle of his everyday life and week-to-week life, he doesn't meet many new, single women and get to know them enough to know that he really likes them. The reason I say that is that, in many cases, when a guy feels as though all the good women are taken, he has gotten to know some women via his social circle or work who already have a boyfriend or husband.

He has been meeting some attractive women who are single, but he doesn't really know how to attract them and pick them up

As a result, single women that he likes may like him as a person or see him as a nice guy, but they won't really be interested in anything s3xual, or in being his girlfriend.  So, if he talks to a woman like that and asks for her phone number, she might say something like, "Sorry, I have a boyfriend." Many women will say something like that to hopefully let a guy down gently. She doesn't want to say, "No, I am not interested in you.
I wouldn't want to be with you. I'm not attracted to you," and so on. Instead, she uses the excuse of, "Sorry, I have a boyfriend." If that happens to a guy on a number of occasions, he may start to believe that all of the women he really likes already have a boyfriend. In almost all cases, though, what he is missing is the ability to attract women as he talks to them. When you know how to attract women as you talk to them and those women are single, that's when you stop hearing, "Sorry, I have a boyfriend" as an excuse to end the interaction, or to let you down gently. Suddenly, many of the single women you meet like you in a s3xual and romantic way and you begin to enjoy your choice of women or you get yourself a girlfriend and settle down.
As mentioned, I'll give you an example of what to say to attract a woman as you talk to her later in the video. For now, another common reason why a guy might feel as though all the women he likes already have a boyfriend is that…

He goes through his everyday life assuming that all pretty women must already have a boyfriend

"60% of unmarried relationships break up within 2 months and 70% end within 1 year." Source: Social Science Data Collection. Stanford University, California The reality is that most new relationships don't work. They don't last, which results in men becoming single again and women becoming single again. When you go into a cafe to order a coffee or some food, the barista may be single. When you're walking through the park and you see a woman with her dog, she may be single. When you're at a bar, most of the women there are going to be single.
Yet, in today's world, a lot of guys tend to think about dating apps and how that is interfering with their dating life and reducing their chances with women. To put it into perspective for you, imagine a woman using a dating app in a big city, for example. Tens of thousands of guys have swiped on her hoping to get a match. Imagine now that she matches up with a hundred of those guys and they start texting her day and night.
Most guys who a woman will match up with on a dating app, will start texting her and texting her and texting her and it becomes way too much to manage. So, what happens for a lot of women, is that they just use dating apps as a source of validation.

He only feels comfortable being himself around women who are taken

So, if he's talking to his friend's girlfriend or wife, then he can feel comfortable because there's no pressure on him. He's not trying to hit on her. He's just hanging out, being himself and talking to her. There's no intention there to pick her up, so he behaves like himself. He's being himself around her. He's being the cool, interesting guy that he is.
Yet, when he's around an attractive girl, an attractive woman that he really likes, then, oh, things suddenly change. Suddenly he becomes more polite, more nice, more reserved, more hesitant than he is or wants to be. The cool, interesting side of him is hidden... So, if you saw a woman in the park with her dog and you found her attractive and she was sitting down with her dog, or she was walking slowly, or just hanging out in the park with her dog, you can walk over and say something like this to her. "Hey, cute dog. It's even cuter than its owner." Pause, smile and add, "Just kidding. It's only a little bit cuter than it's owner.
Hey, I'm Dan, by the way. I was just walking past and I saw you with your dog and I thought, oh cool dog. I'll come over and say hello. What's your dog's name? Maxine. How are you doing little lady? How about you? What's your name? Jenny. Hello, nice to meet you. Can your dog do any tricks? What? You haven't taught her any tricks? Come on.
She's got to be able to do backflips and things like that." You simply keep a conversation going with her.