The question 'What if?', can take us to interesting places.
What if, for example, the London Government Act (LGA) had failed to gain Royal Assent 50 years ago?
For a start, a number of places including Orpington, Bromley and Ilford would still be outside London.
With three million people (as opposed to the 1.75million at present), Essex would be more populous than either Greater Manchester or the West Midlands.
It would also boast its own premier football team in the form of West Ham.
LGA was the act which officially recognised Greater London and redrew the boundaries between London and the counties which surround it.
In one fell legislative swoop, long-standing parts of Essex, Kent, Surrey and Middlesex were suddenly sucked into the new administrative area of Greater London.
The idea behind the changes were to meet the challenges of a growing London.
Creating a Greater London offered economies of scale, room to grow and planning on a greater canvas.
But the reverberations of the LGA are felt even now.
Ask somebody from Romford, for example, where they live and many will say they live in Essex, despite Romford being firmly in the London Borough of Havering.
It is a similar story in Bromley. Many residents say they still feel they are part of Kent, rather than London.
"These identities are very long standing and enduring," says Professor Paul Whiteley, of Essex University's Department of Government. "Identities endure through new political arrangements made for political reasons.
"A lot of people, who have technically been in part of of London for a long time, still think of themselves as Essex people."
Why are these identities so enduring?
Eastender Dick Hobbs, a professor of sociology at Essex University, believes part of the answer lies in deep-seated aspiration.
"Essex was a place to move to and retire to," he said. "People like my parents stuck it out in the east end the whole of their working lives and wanted to spend their twilight years in Essex.
"It is still there now," he said.
So moving to places like Dagenham and Romford was an aspiration achieved. And then, in 1963, those same people found themselves living in east London once again.
But away from the nostalgia and a sense of living in the shires, do boundary changes actually matter?
Prof Whiteley believes they do.
'Shades of grey'
"We would have been better off had this not occurred," he said. "Local government would be stronger. Local government has been marginalised, with funding capped and its powers removed.
"It is not clear why this has happened but it has had the effect of weakening the 'civic culture'."
Colin Smith, deputy leader of the London Borough of Bromley, said there was room for people to have a sense of both living in London and Kent.
"People do fall into two camps," he said. "It tends to be more generationally based than anything else.
"Many people love the green parts of the borough they live in and from that perspective they think it is Kent and I personally agree with them.
"Other people quite rightly point out 'deal with it', it was 50 years ago, you're clearly a part of London' and they're absolutely right too.
"There is no wrong or right, just shades of grey."
Could the boundary changes ever be reversed?
Mr Smith thinks not.
"Oh dear, realistically it is not going to happen," he said.
"We are destined to be best friends and good neighbours with fond memories."