I think that successful people tend to be people who pay a lot of attention to "winning" in as many situations as possible. If you accept losing as a part of life and move on, you're not going to be successful, because you don't spend time thinking how you could've won. Of course this looks funny in situations where one cannot win, but it's really helpful when it comes to fixing your mistakes, allowing you to be successful.
It would be helpful if they'd take a loss as a learning opportunity. But as stated in the original quote they threw a tantrum and accused the opponent of cheating, taking away no lesson to improve the next time around.
* The closer something is to your core business, the less you externalize.
* You always externalize security (unless security is your exclusive core business)
Say you are building a tax calculation web app. You use dependencies for things like the css generation or database access. You do not rely on an external library for tax calculation. You maintain your own code. You might use an external library for handling currencies properly, because it's a tricky math problem. But you may want to use your own fork instead, as it is close to your core business.
On the security side, unless that's your speciality, there's guys out there smarter than you and/or who have dedicated more time and resources than you to figure that stuff out. If you are programming a tax calculation web app you shouldn't be implementing your own authentication algorithm, even if having your tax information secure is one of your core needs. The exception to this is that your core business is literally implementing authentication and nothing else.
https://blog.jonathanoliver.com/ddd-strategic-design-core-su...