to be unable to let pass unnoticed; to be unable to be indifferent; to be unable to just watch (without doing anything)
the greater embraces the less; better too big than too small
to find difficult to guess; to struggle to work out; to be unable to figure out
to be unable to do; to find something difficult to do
to be reluctant to do; to hesitate to do; to refuse to do; to be unable to do
to not understand; to not (quite) know; to be unsure; to be unable to tell
to be reluctant to do; to hesitate to do; to refuse to do; to be unable to do