Sounds like a dumb question. You’re thinking, why didn’t use a stop loss from the start!?!?
I know I know.
Just put yourself in my shoes and imagine a short time frame trade has turned against you while you stepped away from the charts. What do you when you come back and see the big minus sign next to your profit column?
Close the trade right there and cut the loser? Or keep it open hoping price will retrace some to reduce the loss, and maybe even into profit?
You haven’t actually lost until you close. Is it flirting with danger keeping it open even longer?