Today, Taylor Swift turns 21 years old. Although it has only been five years since the release of her first single, the extent to which she has grown as a songwriter and person is apparent. This can be seen when you compare her very first video 'Tim McGraw' to her latest video 'Mine.'

When Swift filmed the video for 'Tim McGraw,' she was only 16 years old. She wrote the lyrics when she was a freshman in high school about a boyfriend who had moved away. Instead of making it sound like a long-term relationship, she changed the lyrics to make it sound like a summer romance: "And I was right there beside him all summer long / And then the time we woke up to find that summer'd gone."

The video pictures a very young and fresh-faced Swift laying beside a pond as she reminisces about the boy that somehow got away. Swift laments her feelings as she sings along to a hand-held radio. She also pictures the sweet and innocent times they used to spend together, like goofing around, walking hand-in-hand and watching the stars.

'Mine,' however, signifies a shift in Swift's thought process; she now has a lot more experience with romance and heartache since her first days as a singer -- with lyrics that exemplify finding the love of her life and building a life with him. She even adds that her parents' relationship showed her a jaded perception of love: "You learn my secrets and you figure out why I'm guarded / You say we'll never make my parents' mistakes."

In the 'Mine' video, she meets a guy who is working as a waiter in a diner, falls in love with him and gets married. However, the video also shows that not every relationship is perfect, with Swift and her "husband" arguing at one point. The pair work out their problems like mature adults and the video ends with Swift, her hubby, and their two children playing at the beach.

It's easy to see how far Swift has come mentally -- no longer focusing on summer flings, but rather turning her attention to finding true love. We have no doubt that Swift's future will be bright and that she will continue to evolve as an artist.

Watch the Taylor Swift 'Tim McGraw' Video

Watch the Taylor Swift 'Mine' Video