It all depends on how old the younger person is... Maturity in a relationship is important and if both parties aren't on the same maturity level, then there will likely be problems. I would say, at 18, you likely haven't experienced as much as you should before entering a relationship with someone who is far past 18. Live a little. Enjoy 18. You have plenty of time to have relationships. After a few years, if your paths cross again, and there's still interest, then you can revisit the idea. :)
Yes, it is. You are at a point of your life when you are still figuring out who you are, where you are going, your purpose, your future, how you feel about things. A 27 year old is way ahead of you. He (or she) might well view you as a youngster to be taken care of, not as an adult on equal terms. That kind of relationship is unhealthy for both of you. The older you two get, the more pronounced the differences will be. It is more than sex and infatuation. In my opinion this is not a healthy relationship.
people are going to have a lot of different opinions about this but i dont think it matters as long as you love or like the person a lot and they treat you good age doesnt matter. & what other people think does not matter as long as your happy.
I used to go out with someone 14 years my senior, and I wound up always feeling pressured by him to act a lot older than I was ready to be. He was always the one who got to call the shots and decide what we'd do, where we'd go, and who we'd hang out with. I broke up with him because I finally realised that he would never treat me as his equal.
It's all well and good to say love is enough, but sooner or later, that age difference will make itself felt.