I get blamed for bad lighting, bad hair, and occasionally bad decisions.

I'll bet you a dollar to a donut that you looked through one of these as a kid. What am I?

I have been burning for billions of years, yet nobody calls me a fire hazard.

What walks on four legs in the morn- wait, what do you mean you've heard that one before? Have you been talking to Oedipus? Alright, smartypants, then how's this for a riddle: Who am I?

You can sit on one, often in a bar, maybe a hightop too; In times gone by, you'd sit on this, to make one, perhaps with a view. A doctor may ask for a sample, though taking a seat is not what they mean; I can be solid or runny, and tell them what your insides have seen.