Being an expert trader doesn't mean that you will be making profits only, there are times you will lose, but your ability to overcome your emotions then and continue to trade and correct the mistakes you have made and overtime turn them to profit is what makes you a professional.
Sorta. I think the most important aspect of being a trader is to be rational and flexible, which means that you should adapt to any sentiment change in the market, despite how much you think your trade will work out.
Most people can't adapt to changes like that, and that's a big contributor to the losses they book. I think there are even some professionals who struggle with that depending on how deep they are into a trade and their win/loss ratio.
At the end of the day, we're all humans, so you can't not be emotional all the time.... even a night with little sleep can contribute to that, or problems in your personal life. We are not machines.