The hardest thing about being philosophically pessimistic is that people, as a rule, are so fatally optimistic, you're still likely to undershoot.
Conversation
The second worst thing is that people always confuse it with dispositional pessimism, and act as if it is.
Replying to
"Gawhd, why are you always complaining? It's like you think we should all crawl into a closet and die."
"Well, no, I enjoy life quite a lot, I just-"
*eye roll*
(Of course, communication style plays a role here - but so do expectations and stereotyping and optimism addiction.)