Give a beggar a horse and he'll ride it to death proverb
People, especially the poor, who gain wealth and power quickly and suddenly, are likely to make bad use of that power and money.
A: He had bequeathed his poor daughter a large amount of money. However, she misspent it all. B: Give a beggar a horse, and he'll ride it to death, you know.
Shortly after an overnight success of John, who used to be an old singer, he was arrested on charges of abuse of power to assault his female colleague sexually.
This phrase comes from a 16th-century proverb that appears in many different wordings, but its complete form is, more or less, ‘set a beggar on horseback and he will ride to (or outride) the devil’
If you fall for someone's trick the first time then they are at fault.
Are you going to mess with me again? Fool me once, shame on you; fool me twice, shame on me.