Contamination
 

I was in the process of making the maiden batch and I found myself wondering if I should put that "thing" in my wort. Furthermore, when I was placing the air lock in the hole the plastic seal fell in the primary. I left it in thinking that my whole arm in their would definitly contaminate the brew. I'm freakin out. Is my brew ruined?

Na its ok, its just your primary, soon it will be buried in yeast. Was it clean and sanitized? If it was clean there will be no trouble

I did that the first time I put an airlock on the primary, no big deal. The yeast will out compete anything that may have gotten in when the seal fell in.

Did the exact same thing with my first batch. :) I was prepared to clean my arm with bleach and go in after it, but we fished it out with the spoon after a few minutes.

I doubt it'll hurt your beer, but it'd be nice to have it in there to seal up your lid.