My worst financial mistake was never really thinking about money or educating myself about it until I was 24 years old. I didn't know what a Stafford loan was and I honestly didn't even realize I had 17k in a school loans until my parents handed over the paperwork after I graduated. Sure I had signed stuff but I never knew for what amount or that I would actually have to pay it all back with interest, because I was naive, confused, and wasn't really paying attention. Fortunately my parents raised me to work hard and live frugally so I wasn't a big spender, but unfortunately they didn't explain much to me about loans, saving, investing, and how money works, so I wasn't a big saver either. It took temping in a financial aid office for me to wake up and educate myself about personal finance and my future. I was (and still am) embarrassed and frustrated that it took me that long and I wasted so many years without saving a dime or learning about money. I wish I could visit myself in high school to kick myself in the butt and tell me to pay attention to how much college will really cost, and to open a savings account and not touch it.