Do I need to know Biology later in life? Or can I throw out all my Biology stuff from last year

It depends on what you plan on doing. I wish I took better notes in some classes and kept all my notes (I kept some, but not all). I regularly refer back to old notes - and in some cases, I no longer have those notes.

Basic biology notes can be thrown out. You can get that out of a textbook or off wikipedia. Specialized or advanced notes are more valuable.

Worse case scenario is it just takes up space in your basement/garage for a few years before you throw it out.

are you going to college or in college? if you are going to college and getting a bachelors of science keep biology with you. in college and you have done all the 'high level' biology needed to meet for biology. then you can throw it out. But it does help start interesting conversations with others.

It depends on what you do with your life. If you become a biomedical researcher, yes, you'll need biology. If you're an accountant, on the other hand, you probably won't be using it much, if ever.

If you enjoyed taking biology, then I'd probably pursue a career there. If not, you might want to pursue something else. As a heads up, if you're looking at going into any true science (biology, engineering, physics, chemistry - social sciences don't count) or psychology, you'll be using it a whole lot.

So to sum it up: Maybe.

Im taking it this year in 9th grade, but im forced to take it this year. If you dont want a profession in Biology then I dont really think you need to take classes for it in the future.