Age difference doesn't matter to that great extent unless you are in love.
Previous to previous generations there were people with the age difference between 5 to 20 years. where 10 years age difference was quite common.
Now with the changing time the age difference has become less - now its anywhere between 0 to 6 years. In certain cases the women is elder by 1-2 years. For celebrities you can't predict the age difference - it can be random -- sometime the lady is 10 years elder to her husband or even more. This is life and it will go on..
The maturity level in a person is also important - as age isn't that important sometimes. But do note that women after a certain age cannot have children (unless you are doing companion marriage) so if you wanted to have kids do keep this in mind - for men although this isn't that big problem. Also law of the country do matters - generally minimum age of marriage for men is 21 while for a women is 18 - anything before it is considered illegal.