I tell you what's not exact. Exactly 4.5 years is not exact.
On 20th October 2008 I left my home in Essex to move to Wellington.
On 20th April 2013 I'll be leaving my home in Wellington to go back to Essex.
You could say this is exactly 4.5 years. But months and years are hardly exact. They're the time equivalent of furlongs, fathoms and Fahrenheit: they have a function, but they're social measurements, not scientific ones. 1 year is mostly 365 days but sometimes 366. Months can never agree on how long they are.
So, while the Earth is generally - pretty much, kind of - on the opposite side of the Sun to when I left the UK, and has gone round 4 and half times, there's nothing exact about it.
Anyway. This is a very vague and rough segueway to symmetry.
Most times when we see symmetry, or think we see symmetry, it's actually nothing of the sort. It's not scientific symmetry, like the curve of a sine wave or crystals on a snowflake; it's made-up, rough-round-the-edges, human symmetry.
As I pack up and get ready to go back to the UK, it's this rough human symmetry that I'm seeing. When I arrived in Wellington, I had whatever clothes and possessions that would fit in a bag and a suitcase. I moved into empty rooms with bare walls and had nothing to put in them. I spent weeks and months gradually gaining new stuff and things, possessions to add colour to my room and underline that this was my room, not just someone else's room, or no-one's room.
Now I'm getting rid of things, throwing/giving stuff away. I'm stripping my possessions down to what'll fit in a suitcase and a bag. My walls are bare, and my room is starting to look sterile and empty - starting to look like no-one's room.
Of course what happens next is completely different to 4.5 years ago. I have 3 weeks of decompression in Bangkok (well, as much as anyone can decompress in Bangkok), and I'm going "back home" instead of arriving wide-eyed in a new city, wondering where the f**k I'll be sleeping. This time I've got a clear idea where I'll be in 6, 12 and 18 months, instead of the edge of the Known World being the end of my visa. (Then again, in Oct 2008 I had a clear idea of going back to London and starting a band in Sept 2009. Hmm.)
I have a feeling that English could do with a new word, that means "not-quite traveller". Someone who is neither a traveller nor settled. Right now, for the second time, I'm reconfiguring for the jump between dimensions - making myself fit to move from one semi-permanent state to another. There'll be lots more of these times ahead.