Jack Nesbaum in the Costa del Sol asked:
Why is memory triggered by smells and music etc?
Smell molecules trigger nerve cells in your nose. These cells then connect to a structure called the olfactory tract and this links up to areas of the brain that are very close to where memories are laid down. This is in a primitive part of the brain, which controls animalistic behaviours such as emotions, sex drive and general arousal. So scientists think that smell can trigger all these other emotions. Also, memories don't seem to be laid down as a video clip, but are distributed all over your brain. So remembering something is like doing a jigsaw puzzle or a collage; the more pieces you have the easier it is to find more.