Just a thought - I see some people in the gym who train different bodyparts with differnet intensities. You mentioned that you "can only think of three bicep exercises". This tells me that you are not real focused on your arm training and may not be taking sets deep in the pain/growth zone.
Get focused and hammer the shit out of them until they have no choice but to grow!!
Get focused and hammer the shit out of them until they have no choice but to grow!!