Seeing as I recently stumbled upon my old diary, I actually do have some good advice for my younger self. Granted, I only read about 3 random entries, but still. Firstly, I would tell myself to be selective of the people that I hung around with. There were times in high school when I didn't hang out with the best crowd, and I'm pretty sure that's because I didn't yet know who I was or what I wanted from myself. I was trying to figure that all out, and because of that, I trusted many people that didn't deserve that much from me and consequently, I got in a few situations because of it.
Secondly, my 16-year-old self should be aware that she does not need to follow in anyone's footsteps. I really hate to say this, but neither of my parent's jobs are much to be desired. My father works for Verizon Wireless doing some sort of sales. My mom is a middle school special education instructor. I grew up being told not to fall into either of those professions. I hold a lot of gratuity for my mom--I think that what she does really does matter and is a hard profession, but the salary is not worth the stress. But when the younger of my brothers went off to college, he found his niche in engineering. Consequently, I followed that path because I had heard of the end results--great job, nice salary, etc--with no regards of the means of getting there. That led me to applying directly for UVa's engineering program to which I was accepted. However, I learned early on that it wasn't my niche. To the advice of some deans and professors, I stayed in it far too long and by the time I chose a different path, there was only so much to choose without having to waste extra time. Needless to say, because of this, I am fully aware that environmental science is not my calling but was more of a fall back to a different science degree. My 16-year-old self should have took more time to really inquire as to what it is she wants to do, within reason, that she's good at and could pursue a career in.
Thirdly, I would tell my 16 year old self not to take fitness for granted and to make it a priority. I definitely peaked in my running the next year, but I could have achieved so much more if I really went for it without any excuses. I would tell her not to let it fall by the wayside with the looming days of college, but if she did, it would come back in a heartbeat. I would tell her to continue the community involvement when she ultimately got to college. I would let her know that although out-of-state is a heck of a lot more expensive, that she should choose somewhere that she wanted to go.
I would also tell her not to waste any time on high school boys, because let's face it--they're ALL immature.