"You're juniors now, I.E you're adults"

At the beginning of this year, I knew that this upcoming school year would be different; now we begin visiting colleges, worrying about our grades, and taking on more responsibility. But what I did not expect was for many of the teachers to use the phrase, "You're juniors now, so you need to figure out what you need and how to manage you're own time." This phrase boggles my mind because I know that I am a junior and that college is honnestly right around the corner but how does this make me an adult. The only thing that I think is different this year than last year is that now, I can drive. This does give me more responsibilty but how does this make me an adult? I can not vote, drink, get married, or enlist in the army but I am considered to be an adult? I understand the thought of preparing us for college and what not but "holding our hands"freshman and sophomore years but then come junior year we are on our almost, kicked out of the nest and told to figure it out on our own. I wish that it had been a slower process over sophomore year and then junior year so that by the end you really feel like an adult more. Senior year is more on the "fend for your self"because it is the last year prior to college but up until then it should be more of a slow process of taking on more responsibility, not just a kick out of the nest. How, at the ripe age of 16, are we considered to be adults in school?