What are your biggest financial regrets?

What’s one of your biggest financial regrets? This might include borrowing too many student loans, making a bad investment, or racking up credit card debt. Note: if you already responded to this query last week, no need to answer again. I’m seeking additional responses but will notify you if I can include yours. Requirements: Please provide a link to an online bio so I can fact-check your name and/or position. Again, no need to respond again if you already sent something to my first query last week.