Scent is the strongest sense tied to memory. It allows us to recall events faster than any other, which makes sense, since there are so many fewer chemical and electrical reactions that need to take place in order for your brain to recall a particular memory. That's why people get all swoony-eyed when they smell cookies (thinking of grandma) or Old Spice (lovable ol' dad).
For me, one of my fastest recall senses is sound. I don't have a competent sounding reason for this, but my sense of hearing is overdeveloped (just go with me on this one) and so sound means a lot to me. I bet I'd kick ass on one of those audio tests where they ask you to identify the sound, and I could correctly answer "it's a short woman using a synthetic-bristle broom upside down to brush the cobwebs off the high ceiling". A gift or a curse.
Music in particular can take me back to places or times and remind me of people. Even incomplete memories -- things that I can identify as being from my childhood, but that I couldn't name a time or place. Listening to my Launchcast station today, I came across this whole stream of songs that gave me flashback after flashback.
"Seasick Yet Still Docked" by Morrissey -- reminds me of a rainy night somewhere around 1998 when Ryan and I were curled up in bed, freezing, and kept losing power in the house (it was downright stormy) but when we did have electricity, we were listening to the Your Arsenal CD and kept getting to this song (3rd, I think) before the power would go out again. It was a nice cozy feeling to be there with him.
"No Woman No Cry" by Bob Marley -- brought me back to the claustrophobia-in-denial feeling of being in the MRI scanner
"Toxic Toast" by the Mighty Mighty Bosstones -- traveling to Boston for New Year's Eve and crying in the Holiday Inn lobby, when they wouldn't let us check in because they had a New Year's Eve policy of not allowing anyone under 21 to check in alone on NYE. I tried explaining to a manager that we were from California, we didn't know where else to go, so he had the shuttle driver take us to about 5 other places before we found somewhere that would let a bunch of 17 and 18 year old kids take a room. Ironically, it was the Crowne Plaza, which was 100x nicer and only $30 or so more expensive. [Also funny : the website now says you must be 21 to rent a room]