why can't I always concentrate my mind , curiosity lost?

I can't figure out why I can not focus my mind on a particular thing and keep it for a fairly long time . always feel tired.
what is the destination and ultimate purpose ? ha, too much consideration about the meaning of life, not a good symbol for a youth, am I youth ? surely I am . ^_^
today is father's day , is my father happy today? I have no courage to tell him that I love him from the very bottom of my heart. I don't want to say too much thing about my father here, every time I think of him , my eyes tend to be wet .
last week an indian called me ,I picked up the phone to answer him, but the quality of the voice was bad, I can not hear him clearly, I wonder what I should do when he call me next time.
Liang li is good girl, really good. she deserve my attention. at least she is better than lots of girls and women around me.