My last job, I was an IT consultant for a five year period of time. In that period, I averaged 150+ nights/year in Marriott hotels (earned a lot of hotel points, Hertz points, airline points, etc.) all over the US and Europe. My boss owned my schedule Monday to Friday and my wife owned my schedule on weekends. Between those two individuals and Google calendar, I never really had need to keep track of my time. My only worry was getting to the electronically-scheduled appointments on time. Absent my eCalendars and the readout on my cell phone, I really had no firm clue of what time or day it was (beyond knowing "it must be M-F since I'm on the road" or "it must be the weekend since I'm home").
I don't think my mind has ever recovered from this. Even now, rolling up on three years since leaving that job, if it ain't on my calendar or I don't have my phone, I don't really know when it is (whatever "it" is).
All of this is prelude/background to why I didn't specifically remember when I spent six weeks - a non-trivial chunk of time - in Memphis. I'd sorta always thought it was 2007. Turns out it was 2008. The only reason I know that it was 2008 was that Flo Rida's _Low_ was all over the goddamned radio in Memphis (and the particular Hertz outlet I was renting from didn't have XM in the cars they were renting me).
I should have remembered it was 2008 because it was shortly after spending six weeks eating lots of barbecue and fried-food in Memphis that I ended up hospitalized with pancreatitis (not related: that was medically-induced because of a toxic reaction to Topamax - a medicine I was on, at the time, for my epilepsy).
You'd think the pain that led to the hospitalization would have been an adequate time-marker for when the Memphis trip happened. But, for as freakishly detailed and complete my memory tends to be, my memories are ordered more in relation to each other than they are to a date on a calendar (*shrug*).
Incidentally, the only reason I know that Low came out in 2008 is because I just got done looking at Flo Rida's Wikipedia entry. And, the reason I was looking at that was because one of his more recent songs was featured in the promotional soundtrack of a Disney movie I'd Stumbled, earlier. I found the video to that song (which led me to Wikipedia) because I'd liked the song in the Disney promo and had punched in "song from wreck it ralph trailer" into Google.