Hey,
I don't think it is strange at all! As long as both of you are on the same line of maturity. I personally wouldn't date someone my age, at all because of my maturity state of mind.
For in the past dating someone my age (I am 19, the guys I dated were round the age of 21) I found them very, very childish and basically not wanting to do anything. Where as now I am going into a relationship with someone who's 28 I found that we balance each other out, and we connect really well. We enjoy each others company, we also discussed what we were looking for in a relationship as well, us both are looking for a same thing. For me and in previous partners we didn't have the same goals, when I and this 28 year old do. Which I think it is now important.
So, I think its down to maturity, and if you connect really well.