You'll make more mature and effective decisions. It can be very confusing to sort out which heart is talking at any one time. Maybe one day I'll consider it. Of course, happiness is more important. But that's just the intellectual understanding of the soul.
Bodily desire confuses our thinking.
Unless you make the effort to distinguish between your wants and your desires, and to clarify which aspect is influencing your actions, then you're likely to lose valuable opportunities to accomplish your goals. What you want to do is usually the right thing, whereas what you feel like doing is often what is the most comfortable thing. The alarm clock goes off in the morning. You want to get out of bed and start your day. But you feel like hitting the snooze button and sleeping late.