This came to mind since I tend to dabble in philosophy a little bit.
Also, yes, I misspelled nihilism. I'm sorry.
If you seriously mix into more than six of these, you'd fall into postmodernism (which grab the "best" parts of each philosophy that existed in the past).
When I was bored in the past, my mind would wander, and I still do wander around. I tend to touch upon sensitive things, especially things like the current problems with doctors not asking to perform autopsies, from which you can learn valuable things about diagnoses and prognoses and etc. The current moral dilemma lies in whether or not one "violated" body is sacrificed for the advancement in medical technology and procedure, and the action that doctors take (most nowadays don't even bother to ask after a patient's death).
Rep is appreciated if you learn something!
It's not very difficult to pop out "oh I am a philosophical" in a conversation, but usually if you do that, you might come off as more of a smartass instead of an intelligent person. So while you can't always use this to boost your ego, at least it would help to keep conversations going, get people something to think about, etc. Most people are able to say this and that about political, economical, social situations, but usually, their views tend to mix into this amalgam of weird and completely twisted ideals (like supporting universal health care, yet saying that people who don't work or are too low an IQ aren't able to get it, and that people with high incomes will still have to pay, etc).
This is a huge issue in today's politics, especially with the whole "legalize marijuana for recreational purposes," which in my opinion is the stupidest thing I have ever seen in my life. I understand the use of marijuana as a medical and utilitarian use (can be used to weave fibers, fire-resistant, etc.), but allowing it for recreational use causes extreme problems, since memory loss from too much marijuana is an extremely significant factor. At least smoking doesn't completely kill off your memory or regular function, I mean, sure it gives you lung cancer, but a pencil pusher doesn't necessarily need to worry about that (no offense to desk jockeys) as a job skill. Oh, and smoking doesn't impair motor function (as if we need more drunk driving-like behavior on roads full of street racing and people falling asleep at the wheel).