My sister recently graduated from college and it took me back to the day I graduated from college. I didn't expect it, but there it was that feeling of accomplishment, sticking to something and getting it done and thinking to yourself I did that. Being in the same building took to take me to that day. Much like the smell of your mother's cooking coming from the kitchen or seeing an item on Ebay that brings you back to your childhood, music can do the same thing. I call it a "3 minute memory." Where were you when you first heard this song? Where you in your car with your friends, at a party dancing to it, working on a project in your home or were you at a wedding?
A good Wedding DJ is trying to create a moment that becomes a memory. They are constantly trying to select that certain song that will pack the dance floor and in essence gives you that "moment to memory" that will last you a lifetime. When you hear that song again, you will think to yourself about the wedding you attended and who you were with and how many laughs you had. Side note, a great photographer will also capture that moment giving you the visual stimulus adding to your experience.
On the outside, it appears that a Wedding DJ has an easy job. Watch them closely, if they are focused on the task at hand (in essence, your wedding) you will see that they are doing everything they can do to make sure your day is perfect and that your BIG DAY will be one of the best days of your life giving you a fond memory for the rest of your life. If you ask a DJ what they do for a living and their response is... "I play music at weddings," immediately look for a Wedding DJ who responds with something like this... "I do my best to put smiles on Brides faces on what is probably the best day of their lives!"