I've got that nervous-but on the right track-excitement about this one.
The milestones we achieve don't always feel like a deadset win and are often scary. There is always an element of the unknown: a chance of failure, making a wrong choice, succeeding(!) and feeling out of your depth.
The Law of the Sea, has fascinated me ever since reading about Russia planting a flag on the arctic seabed in 2007 - claiming sovereignty, declaring their intention to (further) rip up the planet, and starting a bidding war amongst the world's powers for who gets to drill first.
Since then I've been casually learning about government behaviour and the environment, reading things here and there. I mean, "I" couldn't possibly start studying again, right?
I can't tell you about career prospects or salary increases that might come as a result of studying this - it doesn't even align with my current job! But, I'm a believer in engaging with your interests and growing into what (definitely) comes next. If you know what you want, seek it out and begin!