瞎子摸象

xiā zi mō xiàng

1. blind people touch an elephant (idiom, from Nirvana sutra 大般涅槃經|大般涅盘经[da4 ban1 Nie4 pan2 jing1]); fig. unable to see the big picture
2. to mistake the part for the whole
3. unable to see the wood for the trees