I’ve (obviously) never planned ahead financially. When it comes to my student loans, I’ve always just paid off the minimum each month, thinking “What difference does it really make if I put $200/month more towards my loans?” Instead, I used that extra $200/month for nails/clothes/drinks/travel/you name it.
Turns out, that $200/month would have made a LOT of difference, if only I had understood the power of forecasting.