It seems like most older teens are able to fall asleep quickly almost anywhere. I see high school students get on a noisy, lurching, city bus who fall asleep within two minutes of sitting down.
Haha, I absolutely hate naps, and I hardly sleep during the day. I've tried and unless I'm really tired I can't just fall asleep on a whim.
22 year old here. I fall asleep instantly around 11-12, and up until recently, I couldn't nap during the day. A few weeks ago I took a nap after coming home from work at 4pm, woke up at 5pm and was amazed at how good I felt. So now I try to make that a daily thing. It not only gives me more energy for the rest of the day, but it also boosts my mood an incredible amount.
I couldn't take naps when I was your age either, but eventually became extremely able to take naps :)
Also notice how they magically wake up just before their stop? It is the oldest trick in the book to hold on to your seat.
Hey, as one of those people who do actually sleep on buses and can somehow wake up at the right time, I take offence. ;)