Shubho Sashti-r Preeti 'o' Subhechha to all you guys at the very outset.
Well now let me flag on the voyage! Let me start off with the question that created an impact in my mind. Mannan's question... Why wasn't he able to tickle himself? First off, I don't remember where exactly I found the answer and when. I found it years back - probably in the year 1999 or 2000. Here's why can't people tickle themselves:
Getting tickled is an exciting feeling - a feeling that great minds have failed to explain. All you can say is, its amusing... its exciting... its something typical that creates an unexplained feeling. To understand why can't we tickle ourselves, just know why can we tickle others first. Whenever you're tickling your friend, the sensation is soon recognized and picked up by some special nerve endings of his body. These nerves are called "Mechano Receptive Nerves". The Mechano Receptive Nerve endings are located right beneath the skin. These nerves pick up the sensation (information) and transmit it to the spinal chord and thereafter the lower brain stem through some tiny fibers, which are called 'C-Type Fibers'. This entire process of transmission happens very slowly (at a very slow speed), which is why people feel ticklish. During this time of transmission the superficial muscles in our body tend to move to accommodate the sensation. This movement of these muscles are controlled by 'Cerebellum' (The dorsally projecting part of our brain that is mainly concerned with coordination of muscles and the maintenance of equilibrium of the body). Coordination of muscles by cerebellum is not only concerned with the muscular movement, but it controls and arrests them too. The arresting function of the muscular movements by cerebellum is called 'Damping Action'.
Now when you try to tickle yourself your cerebellum gets the information information before ti actually happens. It blocks the process of transmitting the sensation and you don't feel ticklish. So you cannot tickle yourself due to a different process, where your cerebellum detects your self-inflicted touch beforehand and it sends the information to the rest of the brain. The resulting sensation is thus ignored. So no point wasting time trying to fool your brain by tickling yourself.
The mystery 'why can't we tickle ourselves' has been puzzling great minds for years. A pack of British scientists at University College London have solved it.