i know the times i don't have one myself

应该是出自《 善心可依（A Good Heart to Lean on） 》当中的Now that I am older,I believe that is a proper standard by which to judge people,even though I still don't know precisely what a "good heart" is.
“ But I know the times I don't have one myself.”
如今我已经长大成人,我明白了“善良的心”是评价人的恰当的标准,尽管我仍不很清楚它的确切含义,
“但是我却知道我有缺乏善心的时候.”