但除非你承诺要掌握某事，否则就永远没有希望掌握任何事。

But you cannot hope to master anything unless you commit to mastery of one thing.

youdao

所以这段话里的get a real handle on our budget意思是好好掌握我们的家庭开支预算。可见习惯用语get a handle on含义是控制掌握某事。

Let's get a real handle on our budget so we can cut down our spending and start saving some money.

youdao

最后，事后诸葛亮是指决策者相信他们一定掌握了某事的基本情况，他们就能精确的预算出这件事的结果的趋向。

Finally, the hindsight bias is the tendency for decision makers to falsely believe that they would have accurately predicted the outcome of an event once that outcome is actually known.

youdao