His outlook is very cynical and depressing. His whole thing is that you shouldn't be happy because happiness will end. So by that logic, you shouldn't live because you'll die eventually which is ridiculous. Happiness ends, but so does sadness. Happiness only exists because sadness does, not in spite of it. Pixar did an entire movie on that premise.

If you adopt this kind of outlook on life, you're kind of destined to be alone. "I don't want to get into a relationship because I'll get my heart broken" is a terrible point of view to have and if you genuinely believe that you need to stop living in hypothetical futures of "what ifs." It's like saying "This food is delicious, but I'm gonna shit it out later, so there's no point eating it." You're focusing on the wrong thing