If I lose something, I am usually trying to overthink my decisions and to learn from them. Right now, if I lost money, I am doing nothing, because it is too risky to trade to cover the loss and to invest again at the moment, so I am just waiting for better times.
Of course we have to learn from mistakes, most of us are greedy to get big profits so when you keep waiting then what happens is the market drop, then setting a profit target is the most important thing.
Once a loss is already a loss, there is no way for us to recover those losses and yes we have to learn from our mistakes and we need to pay attention to our mistake in order to identify on what is really the root of our loss. After that, we should evaluate ourselves on what we can do better next time to avoid those kind of losses.