i cant understand this its too confusing

__________________
I started playing basketball when I was 14
People always told me what I couldn't do
They told me I couldn't get drafted out of high school
They told me I couldn't win rookie of the year
They told me I couldn't be an all-star
now they tell me i'll never be the same

I dont listen
If I did, you would have never heard of me

-Quote from Amare Stoudemaire Nike commercial