心有余而力不足

unable to do what one hopes to do

xīn yǒu yú ér lì bù zú ㄒㄧㄣ ㄧㄡˇ ㄧㄩˊ ㄦˊ ㄌㄧˋ ㄅㄨˋ ㄗㄨˊ