I spend a lot of time during my day focusing on details. I explain their importance to clients, plan them out, and painstakingly focus on them while I'm on-site.
While details aren't the number one thing that makes a wedding (I believe that's the couple), they play a very strong supporting role.
Details are how you personalize a wedding. Details are how you distinguish your wedding from another. Details are how you imbue you and your fiance's personality into your celebration. Details are how you ensure your wedding will flow seamlessly. Details are often remembered and reminisced about in later years.
One of the reasons you hire a wedding planner is so you don't have to "sweat the details". So I guess it's no surprise that as a wedding planner, I pay attention to the details.