I had a friend in high school. He was nice to me. He drove me to school in the morning with him and a few others, so I wouldn’t have to catch the bus. On my 16th birthday, he gave my boyfriend a dozen roses to give to me (his family owned a florist shop.) When I decided to chop off all my hair randomly one day in the school parking lot, he lent me his katana to do the job. We ran a Dungeons & Dragons game together for awhile, and he always provided enough Mt. Dew and Doritos for everyone.
“Wait,” you may be thinking to yourself. “This guy doesn’t sound like a creeper. He sounds like a nice companion or friend.” And to me he was nice, and a friend. I wasn’t the object of his affection – someone else was. When I met him, he was hung up on a girl bad. He talked about her all the time. He had a keychain lanyard that spelled out her name. They’d never even dated. In fact, when he’d asked her out, she’d clearly said she wasn’t interested in him romantically. He’d been friendzoned, and he wasn’t dealing with it well.
I do imagine he got over her, and knowing the support network he had, I imagine he has amended his creeper ways over the last 13 years. In high school, I knew it bugged me that he wouldn’t just move on, but I didn’t know why. A creeper is someone who behaves in a creepy way. He (or she, or xe) may be a good friend, a courteous host, and a nice companion to others despite being a creeper to one person. It’s so easy to recognize black hat villains, but so hard to see where we are letting things slide or not calling out creeper behavior, because it’s coming from someone we like.
Angie's Anti-Theistic Thoughts 
You’re very observant, here, and it’s good that you bring attention to this. However, I’m afraid calling it out probably wouldn’t have done much good. The one thing you make clear is, he was unsuccessful with his approach. If he’s continuing with an approach that’s unsuccessful, it’s likely because he felt, for whatever reason, he had no other choice, like OCD. In other words, it’s not as simple as it looks on the surface. It’s a symptom of a mental illness.
I had a friend like that, but it was far worse, and as it went on, much creepier. He got obsessed with a girl he had a class. They were friendly for several months, but never dated, and he was still like that with her decades later. He hadn’t spoken to her for all that time, yet, he would keep tabs on where she was living, etc. He remembered dates like when they first spoke, when they did homework together, he had all this memorized. He would go over and over scant time he was with her. All the time, he didn’t want to be doing any of it. He was miserable about it when it got really bad. He knew there was something wrong with it, he was ashamed about it, he had been to counseling,to psychiatrists, etc, and still had the problem. It really brought his life to rack and ruin, and not because of his bothering her, it’s because of how it made him depressed and crippled him otherwise.
If your friend were as good a person as you say, he’s likely mended his ways as much as possible, in that he’s suffered silently with it and has learned to put up a non-creeper visage. Or perhaps got over her and become obsessed with some other woman. Or perhaps it has cleared up, more or less, mental illnesses have cycles. Any way it goes, he’s probably very ashamed, practically mortified, at how he behaved.
Reminds me of SNL’s “The Creep”