As I said, I learned a rare lesson in life. It's staring people in the face but nobody talks about it.
You need to make yourself as healthy as possible and (here goes) practice how to live as long as possible.
It's not as obvious as it sounds - if you really, really knew how important this was you'd do it instantly.
So many people (that were just like you or me one day) get to their 80s and then look back in pain when they realised they hardly did anything! And then they die.
Do you know what it's like being an old person that's soon to die? Do you know how horrible that feels?
As I said, you need to make yourself as healthy as possible and practice how to live as long as possible. There's a lot to say about how you go about doing this. I would say, as soon as possible, start 'trying' to stay as young as possible and live as long as possible. If you keep it in mind as you keep 'trying' to do this, you'll begin to see how you can actually do it.
Imagine, wouldn't you want to be 55 and look like you're 25? You'd be very happy when you got their and realised you'd done it right the entire time.
I'm not talking about medicine or anything like that, I'm talking about having the healthiest/'most long' lifestyle you can have.
Most people don't seem to realise how much they're going to suffer as they get older.
Just do it right, and you'll be very, very happy.