Part of what I like about hiking is the quasi-adventurous nature of it. Sure, there is a clearly marked trail (usually) with a beginning and end. But, you never know exactly what will happen on the trail that day. Could be the weather's unpredictability, a chance meeting with a fellow hiker that may or may not be welcome, or you might see some wildlife that you didn't expect. Even if you take the same hike multiple times, it can be different each time.
I often like that quality. But sometimes, that uncertainty can just be frustrating. Case in point: Big Bend Falls.