临渊羡鱼，不如退而结网

lín yuān xiàn yú, bùrú tuì ér jié wǎng

[It is better to return home and weave net than standing by water and admiring fishes; one should take practical steps to achieve one's aims; It is hard to catch birds with an empty hand; It is vain to fish without a hook, or read without a book] 比喻空怀壮志, 不如实实在在地付诸于行动