Once when I was in college I had 5 days without sleep ( except from short nod aways and zoning outs) with help of friends and energy drinks because I had to turn in a big project. I have a bee sting allergy,and the last day, hours before the teacher received the homework ( he made us wait like for 5 hours) I was at campus and couldn't shake the feeling , that I had a bee on my pants. I heard it buzzing, sensed the wing movements, felt the fuzzy body, and all. I had to run to the bathrooms many times to make sure it was a figment of my mind, and even so I was sure it was on me.