Well I think if you're in this world you should find a way to live it to the fullest. Plenty of people die without ever getting a girlfriend. It's not a bad thing. Maybe in a biological way it is because you won't be able to pass down your genes but I believe humans are more complex than this because of our brains. The fact that you were born is a biological success in of itself so you should love yourself for that. You made it to this world! And I'm not sure about you or anyone else but I have no idea what comes after this life so I figure I might as well enjoy the ride through all the ups and downs while I'm here because I have no idea if I'll ever be able to experience it again. I'd argue there's no blueprint except for the one we create for ourselves.
As for love.......try love in it's simplest forms. Go out and make someone's day. I'm surprised how often I forget just how good it feels to share a meal with someone even if it's just a coworker or a sibling. Lend a hand to someone without expecting anything in return. Lending a hand doesn't necessarily mean pulling out your wallet and giving someone on the street corner money. Sometimes it's as simple as giving someone a friendly smile or chatting with someone at a bus stop. Take care of your mind and body and you'll feel a whole lot more loved from someone who means it the most.....YOU.
As for women, they're beautiful beings but they won't all find you lovable just as we don't find all of them lovable and that's okay. It doesn't make you a meaningless person unless you let that define you. Take me for example: I'm 25 years old and I've never had a girlfriend either. I'm actually quite pathetic and I rank pretty low on the social hierarchy. I've got 2 DUI's and I go to jail in 8 days. I lost my car, lost my phone, 95% of my money, moved back in with my forgiving mom, lost my job, lost my friends, etc. So yes I'm definitely not someone you should aspire to be but despite all this...I live on. Will I ever have a girlfriend? I don't know. If I do then cool, if not then that's cool too. I just know I really wanna play the piano to my hearts content. The sound of the piano makes staying on this roller coaster worth it despite all the bad things that are going on in my life.
You never know man, some lady might come to love you some day but for now I say find your "piano" and do it.
PS: I misinterpreted this question. I thought you were saying that YOU never had a girlfriend. Either way I think he should read what I had to say if he's feeling down.
