Yes, being shy and being in EMS is like oil and water. You will have to touch, prod, gropue and fondle complete strangers while being watched by, in some cases hundreds people (even in a classroom setting you have groups of people watching everything you do). You have to delve into peoples personal lives, some people are rude, mean and nasty and those are the patients.
So...yeah if your shy, I suggest getting over it quick, you cant be shy and do an assesment. Ive seen shy people freeze up, cry (I mean completly break down), ask people to leave, ask the patient to be nicer. Run out of the room because the Instructor yelled at them (Your patient is going to die! dont @#$! worry about the 12 people staring at you hes bleeding to death!) In EMS (especially in the field) everything you do is scrutenized, recorded, taped, and examined. You cant ask 100 people gawking at some guy who cant breathe to kindly go about their business. heck most of the time you have to punch, kick and shove your way through the crowd just to get to a patient.
Good luck, hope it helps.