purely enjoyable that you might not even notice it 
(ROOT (ADJP (RB purely) (JJ enjoyable) (SBAR (IN that) (S (NP (PRP you)) (VP (MD might) (RB not) (ADVP (RB even)) (VP (VB notice) (NP (PRP it))))))))
(ROOT (ADJP (RB ) (JJ ) (SBAR (IN ) (S (NP (PRP )) (VP (MD ) (RB ) (ADVP (RB )) (VP (VB ) (NP (PRP ))))))))