This is true because we are dealing with something that is filled with stress, at least for most people and that is why it is not that easy to make sure that you could just stay calm while you need to stay calm. If you are going through some rough part of your life then trading on top of that could cause you to have bad reactions to some mistakes and cause you to make even bigger mistakes as well resulting with you making even bigger loss too, which is why it is understandable that people need to feel better before they could start trading.
I personally also suggest that if the stress becomes too big, then taking a break also helps as well. You do not have to be going through a rough time, if trading becomes a chore and not something you enjoy doing then you better end up taking a break.
Of course, all things related to profits or losses which essentially involve finances can make us stressed if we ourselves are wrong from the start, when they experience losses or lose money and when they cannot accept it, it is very possible that it can be stressful. If you are experiencing or experiencing problems in life, it is best not to trade, because confused thinking can make us take actions that are not considered, possibly taking careless actions that can ultimately harm ourselves.
If we are indeed experiencing a problem then what we have to do is rest and think about a way out of the problem that is occurring. it is impossible to continue what is being done, especially if our condition is not well, it could possibly cause us to experience more serious problems.