Cold feet.
More Traditional Proverbs:
Get your feet on the ground.Traditional
A neighbors hen looks as big as a goose, and his wife as young as a girl.
Traditional
The word that is heard perishes, but the letter that is written remains.
Traditional
Every man is rich in excuses to safeguard his prejudices, his instincts, and his opinions.
Traditional
Life is like an onion. You peel it off layer by layer and sometimes you weep.
Traditional
Always put off until tomorrow the things you shouldn't do at all.
Traditional