Heads I win, tails you lose humorous
Used to say that no matter what happens, I will win
He was so arrogant that he supposed it was a heads-I-win-tails-you lose case. At last, he had to beg for help from his father.
Flipping a coin is my forte. Heads I win, tails you lose.
The expression is used at the beginning of a competition to say that you hope the most fastest, strongest, or most skilled succeed person
wins.
To win only by a smaill amount; to win narrowly
A game in which all sides have potential to win
Win something easily, or with less or no effort
The phrase "heads I win (and) tails you lose" is first recorded in The Second Essay on the Catholick-religion: Viz. On Its Suppression and the Substitution of Heathenism, or Idolatry (London: Printed for John Worrall, 1728), by Guy Vane—as quoted in the Oxford English Dictionary (online edition, March 2021).
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.