I think maturity is the real issue, not so much age. Because maturity is so important, that's why it might be weird for a freshman in HS to date a senior. Everyone is at different maturity levels...I'm 19 and mature for my age. I always have been. My girlfriend is only 2 months older than I am, and she is also very mature for her age, and always has been. If she was still my age, but much more immature, I don't think there would be any attraction. I think maturity really encompasses a lot of your behavior, ways of thinking, etc. So when the maturity levels are different, at least from my perspective, it wouldn't work. Not for me in relationships, at least. I think that may be the same for others. I also don't see how I could be in a relationship with someone with political views far different than mine, or someone who was extremely religious. Opposites don't always attract. That's a common saying, but often times couples have more in common with each other.