All that Glitters is not Gold
Whoever said: "It's not over till it's over" was probably a Chess player. You can be winning a game and then your opponent makes one of those out-of-the-blue moves that forces your immediate resignation. Such moves are not always final, you might realize a little too late that you threw the towel too soon, and perhaps, the game could be saved by a miraculous move you just failed to see on time.
Take the position below for instance, White is three pawns to the good and understandably happy in his situation. Black's fantastic reply soon shatters his happiness, and yet, White manages to make a masterly recovery before it's too late.