Parent

Time flies and it gives the lessons.

And believe me: your biggest regret is you won't hear your mother and father in the past.

When you know how hard they work for you, your heart beats fast and everything looks so dark, you'll do the best for them and feel sorry for everything. How lucky you are if you realize it early. I mean, you realize it when you are young. 

Now, I do believe that every people fight for their life, and our parent fight the most.