I finished school this year and my favourite subject is definitely physics.
My favourite thing about it is that if you can think of it, physics can quantify it. It's the father of all science.
You look to the stars and you can describe what you see with physics, you look at the tiniest sub particle and physics can describe it.
From quarks to quasars it's just the most amazing thing you can get your teeth into, you can spend your whole life learning and never even scratch the surface of it. Isn't that just amazing?