This is a very good advice coming from an experience person.Trading based on emotions is very risky and often results to loss of funds.One should play it safe when it comes to trading because market can be very manipulative at times.one need to stay calm and focused.
Being at your control at most times when you trade is needed. You're like the captain of your boat and if you don't calmly control it, your boat will sink as if it is your money in projection.
And listening to others advise is a good treatment from how you're trading. Because you'll have your own experiences as well and from there, you'll see that you shouldn't trigger yourself by having mixed emotions in trading.
Besides, we don't need to stop everything and feel nothing. We can still have those emotions (positive and negative) but of course, the most important is we know how to manage ourselves when it comes to making a decision.
I agree, managing your emotions while making decisions plays a big part of your trading results. If you don't manage them and you're too emotional for it, you'll be unfocused.