Английский словарь американских идиом - find one's ---

{v. phr.} To become able to use (some power of the body or mind.) * /In the program for the parents, John was nervous and could not speak at first; then he found his tongue./ * /The young bird had just found its wings./ * /The baby was just beginning to find his feet./ * /The question surprised him, and it was a minute before he found his tongue./