What are your biggest financial regrets?

Seeking sources to share their biggest financial regrets. These might include taking on too much debt, making a bad investment, or choosing the wrong job. Requirements: Please provide details of your ‘financial regret’ in your response to this query. You also must have some way to verify your identity, like an online bio or other documentation. I will especially prioritize sources who are willing to share their story with other journalists, in case the opportunity comes up.