thunderbolt headaches

so whats the deal with the thunderbolt interface it seems that if i try to run multiple displays, i cannot. but everything that i have seen says that it can, so is it the GPU (on the CPU die of my MBP)? or is there some other reason that Apple has done to the first generation of thunderbolt?

Which model MacBook Pro and how many thunderbolt output ports does it have? My 2013 iMac for example has two thunderbolt output ports which will accommodate an external monitor on each port.

mid-2012 13"

Your Mid 2012 13" MacBook Pro has one Thunderbolt output port which means you can run one external display. You can attach multiple displays (2) with an additional device.