A spendthrift, having wasted his fortune and left with only the clothes on his back, saw a swallow on a fine early spring day. Believing summer had arrived, he sold his coat for whatever he could get. However, the weather suddenly changed; a sharp frost came and killed the unfortunate swallow. Upon seeing its dead body, the spendthrift cried, "Miserable bird! Thanks to you I am perishing of cold myself."
One swallow does not make summer.