Regardless of how you style your hair now, changing the length and shape periodically can help you keep up with the "natural changes" your hair and facial features under go with time. What once worked well when you were young may not work as well as you age.
It may come as a surprise but if you look closely you'll find that many of the classic hairstyles are the result of what each hair type does naturally and uniquely. With few exceptions, I've found that almost everyone's natural hair type suits them best when "cut-shaped-styled" to bring out its hidden beauty.
The secret to finding the "perfect hairstyle" is to simply work with what the hair does naturally and design your style around it. With a custom shaping you can easily dress it up or simply shampoo, comb and go. You'll save time and always look good even when you don't have time to style your hair. However, the shape and length must also complement your face shape and most importantly your unique facial features.
The most important thing to remember is do the best you can with what you have. If you're not happy with what your hair does, or looks like naturally there are countless ways to change it. But keep in mind that none of these things are permanent. Your hair can be one your most unique features. I always suggest trying to work within the boundries you've been given rather than trying to break those boundries.