Being mindful helps you from getting stuck with thoughts or feelings that limit your imagination and experience. Looking at that more positively – it helps you experience more of the substance of your life rather than getting distracted from what is actually going on. The advantages are being to respond more effectively to challenges, and not coincidentally feeling better. This is a well-validated measure of mindfulness. You could use this as a part of checking your progress – your first result gives you a baseline, and from that you can experiment with what helps your positive mindfulness.