Think of your greatest accomplishments.
( ( Think ( of ( your ( greatest accomplishments ) ) ) ) . )
(ROOT (S (VP (VB Think) (PP (IN of) (NP (PRP$ your) (JJS greatest) (NNS accomplishments)))) (. .)))
Think about how many times you have failed. 
( ( Think ( ( about ( ( how many ) times ) ) ( you ( have failed ) ) ) ) . )
(ROOT (S (VP (VB Think) (SBAR (WHPP (IN about) (WHNP (WHADJP (WRB how) (JJ many)) (NNS times))) (S (NP (PRP you)) (VP (VBP have) (VP (VBN failed)))))) (. .)))