remember back when thrillers actually thrilled ? 
(ROOT (S (VP (VB remember) (ADVP (RB back) (SBAR (WHADVP (WRB when)) (S (NP (NNS thrillers)) (ADVP (RB actually)) (VP (VBD thrilled)))))) (. ?)))
(ROOT (S (VP (VB ) (ADVP (RB ) (SBAR (WHADVP (WRB )) (S (NP (NNS )) (ADVP (RB )) (VP (VBD )))))) (. )))