When you buy a pack of cards at the store do you open it there or can you wait until you get home? Do you open it up on the train or in your car or wait until you get home? You can be a 50 year old or a 10 year old and the anticipation is usually too great to wait. You can picture all the possibilities of what you might get when you open a pack. Clemente, Ruth, Mantle, Pujols or the new upstart rookie.
There is also the anticipation of a new card design. Will they be as special as the ads say or will they fizzle. You don't really care when you open the pack as that anticipation makes it all worth while.
For me and for many others the anticipation of opening the pack or a new box is what the fun of card collecting is all about.