For checking the transcript: https://www.buzzsprout.com/2379282
Once bitten, twice shy
means that when someone has had a bad experience, they are more cautious about similar situations in the future.
Examples:
1- After buying a faulty car from a second-hand dealer, Matt only buys brand-new cars now. Once bitten, twice shy.
2- The company partnered with an unreliable supplier last year. Now, they run thorough background checks on new vendors. Once bitten, twice shy.