The feelings are just one thing, that's true, that one we can chose, but we can lose so many other things because of some toxic relationship, bad friend, abusive partner... Our job, friends, personal happiness, family... name it. Think positive gives an advantage because there is a little to no loss of energy to irrelevant things, but then again we might earn a title of being unemotional as well. Depends who is watching and depends, on the other side, should we care ( not).
Stay well!