Do you take advantage of school and enough to care about what the real world would look like when you graduate?

High school absolutely makes a difference in your life (and the real world). While it's great to have friends and participate in other activities, grades and learning are essential to further your education with college, or just to have the tools you need in the real world. Obviously not all high school subjects are going to relate to your career (eg: I haven't used calculus since 12th grade!), but other things are skills that you'll use forever. Learning how to write and also understanding the context of a writing, as well as basic math and problem solving are something that will follow you forever. And sad to say, but high school grades make a difference if you want to go into the professional world. High school grades determine where you go to college, which can then determine where you get a job. I'm not saying that it's impossible to succeed without having good grades in school, but it certainly doesn't help.

Echoing what was said above high school definitely does matter for your future success. Even more so than the content learned in class it is the skills that you are developing, learning how to manage multiple commitments at once (classes, extracurriculars, friends, family), communication skills (both written and verbal) and starting to discover what you are most passionate about. If you learn good habits while you are still in high school you will have a much easier transition to college and eventually to the "real world."