Does age really matter?

How big of an age gap really matters?  5 years?  10 years?  15 years?  Women in their 40's who date/pursue younger guys are called cougars, and women in their 30's (like me) are called Pumas.   I love that term.  Although I don't know if I'm looking for a younger guy?

I went on a date with a older man (9 years older) who has older kids.  I would have never have guessed, he looks significantly younger than that.  I mean, does it really matter?  He doesn't act older and besides the fact that my age is half way between his and his daughters, I don't see much of a difference.

I read this article about age gaps and how NOT to treat your significant other, so I guess as long at I take their suggestions in to consideration, I'm good.