Is it possible to have an ear infection without knowing?

Ear infection: Not very likely. You might have mild symptoms, but i've never seen an adult who didn't notice that something was amiss. Most suffer hearing loss in the affected ear. Most also have some pain, but the pain could vary from almost nothing to excruciatingly severe. Ear drainage can also occur and this could range from clear mucous-like material to brown bloody pus (really gross and disgusting).