I see nothing wrong with this. First you're 28. Not like you're 48. Plus, many people are older in college now, and that age gap isn't much. Also, many take 5 years to get out of university due to the increase in state requirement classes. You drop a few classes or fail one and you can be going 4.5 to 5 years if you don't take summer courses. My HB9 cousin was like that at Mizzou. Took her 5.5 years due to dropping classes because of poor performance. Also joined the sorority which IMO a distraction at a school like that.
When I went back to college at age 27, going on 28 in the fall back in 2011 I really had no problem blending in with the student body. My school was in a major city, private liberal arts college, pretty expensive but being a major city many were commuter students. No one questioned my age and I had friends quite younger than me and I even went to student orientation and the field trip to bowling and for the hell with it got a number from an 18 year old HB9 and 18 year old HB7 and some other chick who was probably HB8, can't remember. Key is not acting creepy. I also think those 18 year olds don't have much experience which is why it's so easy getting a number. They don't have their b*tch radars up yet. Women under 22 have not been around long enough yet. Most of their experience is through school. When they're hot and 29 their b*tch radar is now finely tuned. The best time to cold approach in your life is when you're a young lad in college or high school. The women don't have their full b*tch, jaded radars up yet. Young men under 25 should not even be looking at OLD.
Reminds me of a couple other times too. Another time, a year later I had to take some stupid AF art appreciation class for required elective. All of us had like Cs in the class. Being a business major I was bored of it and hated it. So the hottest chick on campus, she was 23 or so and a fashion model. Easily HB9.5. Probably would be a famous model had she been taller (was about 5-6). Anyway, was from a rich part of town, total snob to everyone around here like she was better than us, always talked down to the other students like they were stupid, kissed arse to the teacher (would always skip the required field trips) and overall a b*tch and literally no one on campus would hang around here. Anyway one day finally decided to small talk, and actually opened her up a bit and was one of the only people she'd chat with or talk to. Opened up a bit in email to me.
I still also remember the time I took a summer credit in community college for gym credit. Was a stupid pliates class but decided heck I'd save money taking it at community college and figure it would be all chicks. Only two guys in the class, but only 3 of the chicks were hot, one was engaged, other had a bf. However, the hottest one I happened to scope my spot out and sat next to her. 5-10, skinny, blonde hair, blue eyes. Easily HB9. I spied facebook and saw she had a boyfriend. So just chattered her up and was friendly. Eventually after class just cold approach her walking out to our cars and flat out asked for her number. She tells me to drop my back pack and whip my phone out and she puts her number in it. Texted back and forth for awhile then she admitted she had a boyfriend (she didn't know I knew lol.)
I also pass off as really young even at my age now. When I was a freshman at the university level everyone though I was skinny and worked out a lot. My first year mentor which we get all assigned at orientation which is an orientation leader was a chick. When she wished me happy birthday I somehow told her my age and was totally shocked when I told her.
Sooo, if you really are 28 just be in good shape and look young and cold approach. These 18-23 year old women are much easier to cold approach than women in your age range who have defense mechanisms up.