It is our nature to strive for the positive, while seeking to Avoid the Negative emotions (think Stress, Denial, Fear of Missing Out). It’s the reason why it’s easier to give in to that ice cream sundae (Momentary positive), even though it’s not in line with your big picture (but that’s the Future You’s problem).
The problem is that Emotions are Short Lived, and that fleeting positive feeling from the ice cream quickly turns negative when we realise we’ve strayed from our plan. These negative feelings can once again lead us to search out a temporary positive, as we start searching for another mental ice cream sundae.