Dear child, (speaking like a real old person :p)
Cherish every moment. Embrace them like they're the last. Never think too much of the future as it is uncertain. Never regret your past as they're what you make of yourself now.
And last but not least, a little bit cliche of Malaysians ; "Hidup hanya sekali, jom kita enjoy!" What kind of $*** is that? Life is paradox. So, be good like you're going to meet your God tomorrow. And work hard like your life will go on until all your teeth fall off, and so, you need to buy a set of false one. (Well, it's not cheap I know that)