I see on this thread,that like me,smells seem to be the most evocative sense to trigger a memory. I noticed this phenomenon many years ago and was curious as to why this was. The scientific explanation (put simply!) is as follows;- 'The olfactory bub which starts inside the nose,runs along the bottom of the brain and has direct connections to 2 brain areas that are strongly implicated in emotion and memory,the amygdala and the hippocampus. Interestingly,visual,auditory and and tactile (touch) do not run through these brain areas. This is probably why olfaction (smell) more than any other sense is so successful in triggering emotions and memories'. I find that the smell of creosote,used for weather-proofing fences takes me back over 45 years to when I was 5,and going out into the garden just after my DD had done the annual fence maintenance.