Going to the casino made him realized his weakness in his business which he turned it into his strength, because he started all over again.
The chance of winning big in casinos are very slim.
And "fate" is what drives people to do absurd things thinking that they can replicate what others did because they feel like they're destined for that same thing. News flash: they're not. Smith is not only a lucky man but also a smart one that recognizes his situation and bailed out after he got something out of his luck. Most people would have continued playing because they believe they can get more. Perhaps Smith's business (FedEx) also helped him have a clear mind when it comes to such decisions. He knows his priorities and he knows what's best for him and his company.