Daily Dose of BS Aug 25 stocks

I am not a financial planner nor do I play one on the radio, however my dad is one and I have many friends who are.  On Monday the market opened then immediately lost over a thousand points.  What does this mean to the typical person?  Well in my understanding is that if you were to sell your shares of stock when your shares were down, then you lose some money, however if you were to buy stocks when the market was down, it would be like buying those stocks on sale.  When the market has big swings you don’t really lose money or make money unless you decide to make a sale on that day at that time.  My dad once explained it to me if you buy a stock for 100 dollars and you lose 50% you are down to 50 bucks but if you gain 50% you are only at 75 dollars.  I guess the way I look at it for me, is that I don’t need my stocks today, so I am going to just let the shares ride, so no loss, except for on paper.