“That sucks” is negativity. “That sucks, here’s why, and here’s how to fix it” is criticism, ​ Someone with an informed, critical opinion is, in my experience, far less likely to be negative than someone not as informed. If anything, critical thinking adds dimension to an appreciation of the world around you.

the kinds of emotional intelligence one needs to succeed in a field where you spend almost all of your time understanding nothing. ​ And second, by presenting them with a formal definition, I gave them a common reference point from which they could compare and contrast their own notions. There we had the beginnings of disaster avoidance. ​ As a mathematician, Devlin did nothing unusual. In fact, the most common question a mathematician has when encountering a new topic is, “What exactly do you mean by that word?” ​ The mathematical habit is putting your personal pride or embarrassment aside for the sake of insight.