Ticks!

...one was head deep in my bicep. I found him when I returned home 10 hours later from the camp.......bicep survived; tick did not.

If one has hair on one's body and pays attention, one can usually feel them as they locate to a nice spot.  If you have smooth legs, too bad.  There are repellents that work, but self awareness is best.  They hardly ever settle on a smooth, open (hairless) spot.  Nape of neck is a favorite.  If you will be attending the festival, you will be exposed to ticks in the fields, despite Tucker's best efforts to collect them all.

If using repellents with pyrethrim, read and follow directions carefully--they usually include things like spray in a well ventilated area 12 hours before exposure and usually you are spraying your shoes, socks and other clothing, not your body.  Pyrethrims are not chemcials you really want on your skin.  Even "plain old" DEET in high enough concentrations will take the paint off pencils and dissolve rubber.  If you plan on sweating, watch you forehead application and hands as well. 

When checking yourself for ticks make sure to check the warmest areas of your body as that is the most common place to find them - armpits, back of neck, behind ears, groin, etc.  If you find one don't try to pull it off or squeeze it. Put vaseline, baby oil, or olive/vegetable oil on it then remove with tweezers. The oils will cause the tick to dislodge itself making it easier to remove and less likely that it will transmit any diseases.

If you start feeling flu-like symptions within a week or two of being in the woods make sure to go to a doctor immediately to start antibiotics.

If you're already a Lyme Disease carrier (i.e. been bitten by a tick before, showed symptoms, and will now come up positive the rest of your life), can a bite "infect" you a second time? Cause a flare up?

I already went through that once. It sucked .

As someone who has in the past and is again working as a secretary for a Lymes disease specialist, I feel qualified to answer this question.

Not everyone that has been bitten by a tick and gotten an positive test result will test positive the rest of their lives.  If you are bitten, show symptoms, and are treated with the standard dose of strong antibiotics within the first few few months, more often than not the disease will be treated and will leave the system.  After that, if you are bitten again or show symptoms again, you should be treated again.  That does not necessarily mean you are carrier, just that you've been reinfected.

There are however growing numbers of people that do carry the disease, and cannot get rid of it.  This typically occurs when the infection was not found and treated within the first several months.  Interestingly, a small number of these cases never show up positive on the standard Lymes disease blood tests, or show up positive on some but not on others, or only show positive on spinal taps, etc (there are several blood tests, some better than others depending on the particular case).  That being said, for those people with recurring Lymes disease, it typically lies dormant in the system (usually not showing up in any tests at this time).   Flare ups can occur sporadically, under certain stressors, or the symptoms can simply stick around permanently, never going dormant and only able to be managed by Lymes-literate doctors and the right mixes of medication.  

So to specifically answer your question:  If you have had Lymes in the past and gotten rid of it, yes you can be reinfected with the disease a second time.  If you have recurring Lymes disease that is currently lying dormant, yes it is possible for a new bite to cause a flare up or second infection.  Either way, only a certified physician can tell you the right course of action, so see a doctor if you have any suspicion of symptoms in order to have the best chance of fighting it.