How Original Are Our Original Ideas?

I have a friend who was recently engaged with and surrounded by "Trolls" on Twitter. For those two or three who haven't encountered a troll on the internet it is "a person who posts outrageous message to bait people to answer. Forum Troll delights in sowing discord on the forums. A troll is someone who inspires flaming rhetoric, someone who is purposely provoking and pulling people into flaming discussion. Flaming discussions usually end with name calling and a flame war." (http://curezone.com/forums/troll.asp)

Anyway I decided to draw a big hairy troll scarfing down Purina Troll Chow for his amusement. I was disappointed because he just wouldn't cooperate when I tried to draw a big hairy brute but I learned long ago to let the character develop naturally rather than fighting.

When I showed the pic to my sister she asked, "Where have I seen this troll before?" I replied that I didn't know, that I had just drawn it. But I got to thinking, pondering, wondering..... Had I seen someone else's troll and had he somehow buried himself inside my subconscious mind to be manifested onto my drawing pad when I decided to draw my own troll?

I posted him in a couple of groups I belong to on here and one member cleared up the whole mystery. Here's my troll and the photo the other member posted.....





Now I have never been ashamed to admit that I'm a huge fan of Star Trek and have always been and here's proof! Also clears up the reason I couldn't draw him more "trollish" looking. Nelix was a gentleman and would never go out unless well groomed.

The likeness is better than if I had tried to dress Nelix in summer casual attire and give him a bag of Troll Mix but he and Star Trek were the farthest from my mind when I drew the above picture. Which brings me to another question:

How much stuff (artwork, music, written stories, etc) that we create is really from our own imagination and how much comes from other stuff we take in? Or is it all melded together in the wacky world of our imagination?

There has been in the news countless times over the years where someone sued a song writer for stealing their song, cord progression, lyrics..... and the defendant says they didn't steal anything "I woke up with the tune in my head" I can see both sides there...I wake up with a tune in my head all the time but I know I have absolutely no song writing ability and therefore know there's no way that can be MY song!

But at the same time I don't believe the accused artist meant to steal anyone else's work any more than I meant to draw Nelix when I set out to draw a big hairy brute (he was supposed to wear high top Converse sneakers but Nelix refused)

I don't have any real answers here....just worrying a thread that's been hanging around in my mind and also wanted to show off my troll (AKA Malibu Nelix)