There are two levels to appreciation:
The first is what happens when we see a daredevil fly through the sky or encounter the Eiffel Tower for the first time. We're amazed and we sit and marvel, overcome by someone's skill and passion. We can't believe what we're seeing so we bask in awe.
But many times, we can go deeper, if we've got the knowledge or background. The architect appreciates the Chicago skyline more than me because she knows the learning and detail that goes into that kind of creation. Dancers appreciate movement more deeply when they watch it because they identify with all that lies beneath what is being showcased on stage for all of us to gawk at in fascination.
Perhaps there is yet a deeper level, too, though. Perhaps once you identify with an art form or object, you are so gripped that you want to reciprocate. You feel something deep within and the only way to acknowledge this appreciation is to yourself create something. This is your tribute. You were so inspired that you needed to honor that which you witnessed with art of your own, art that in turn fascinates, identifies, and leads to creation by others.
Appreciation is not limited to art or architecture, of course. You can appreciate a company, a teacher, a city park, a time of year, a story, a friendship, or a meal. And when you do - when you feel it deeply - then it's time to go make something great yourself.