Time and careful planning are what you need to retire and live happily ever after, but sadly often life gets in the way. (Coronavirus would be a good example.) No one is perfect, and many retirees have regrets when they reach retirement. We've talked to both senior financial planning experts and retirees alike about some common regrets. If you aren't at retirement age, then you've still got time to right some of these so you can retire regret-free.