Interest as a state — the desire to achieve the goal as a state of mind, soul and body.
Interest as a state may differ from interest as a lens: a person caught fire with something, then went out — his state of interest changes, although nothing objectively has changed.
Goal definition
Are my goals ambitious enough? Rate your goals correctly in terms of difficulty. A goal of little difficulty will not motivate you to achieve it. And if the goal is too difficult for you, then you may not get the desired result.