This country has changed and so has sentiment in the City. That change doesn't just apply to the future of London as a financial centre, but to the interaction between generations and nationalities in the office.

As a long time City professional (currently in my late-50s) working in a leading investment bank I am surrounded by many colleagues who are typically 20-30 years younger than I am. I am a so-called 'Baby Boomer;' many of my colleagues are members of the so-called 'Millennial generation.'

When I confessed to being in the "out" camp before last week's Brexit vote, those Millennial colleagues indulged me. I didn't vote out for xenophobic reasons (although I do believe there are some real capacity issues with the infrastructure of this country) and nor did I vote out because I wanted the UK to trade with the "rest of the world" outside Europe. I vote out because I have long doubted the drive to increasing to political and fiscal union within the EU. In this context, I was skeptical about the UK's real influence with other EU members. And I wanted change - and a leave vote seemed the only way of supporting this.

As the referendum approached, I shared my thoughts with my younger colleagues. I also expressed my feeling that prevailing social issues and widespread distrust in the establishment would, along with generational bias, made Brexit a real possibility.

Did they listen? No. I was smiled at and condescended to and considered to be misguided. In their eyes, the case for Remain was "strong and obvious." That complacency was to bite back.

One week later, I'm very unhappy with my treatment at the hands of a good number of my fellow City workers. I've been accused of being "un-British," and I've effectively been shunned. Many claim to be "so upset" that they won't even talk about the result. Those that do speak are considering protesting and demanding another referendum because not enough of the younger generation voted!!! Is this how they want democracy to work? - Voting and re-voting until they get the answer they want?

Many of my colleagues seem to be experiencing something akin to a bereavement. By voting "selfishly based upon the past", they feel that the, "older generation," has stolen their birthright. Last week, they were all merrily complacent. This week they're infused with a passion that was completely absent as the referendum approached. Like children, they're stamping their feet and complaining about a toy which they previously took for granted being swapped for a different one. Yesterday, a colleague said, "The British do not discuss sex, religion or politics at the dinner table, so will you please refrain from discussing the Brexit vote with me."

Maybe my younger co-workers should pay more attention to the wisdom that comes with experience? Instead of demanding another vote - or demanding that the older generation should be excluded from future referendums - consider that the older generation may have more perspective from which to judge a decision. Imagine the response if I suggested that anyone under 30 might not have sufficient experience to judge the outcome of their decision!

If you work in the City, you are living and working in a bubble within a bubble. The first is financial services, the second is London. You are an elite member of this society in terms of wages, wealth and opportunity. As such, you likely have a very gilded view of life. Now, believe me - the rest of the UK is very different, and if you live in London you are part of the UK.

My colleagues don't seem to appreciate this. When I point out London's exceptionalism, they simply shrug as if to say, "so what?" They might admit that they didn't realize quite how disparate London is from the rest of the country, but they don't want this to change. Instead, some of them are even suggesting that London seek "independence." In this sense, they are simply looking out for themselves without even considering the interests of the nation as a whole - in other words, being as self-centered as those they accuse of voting against their interest.

I have been in the City for a long time, but today I am not proud of many colleagues. I have seen many ups and downs, good and bad behaviour, and whilst I've acknowledged the undesirable aspects of the City I've generally defended it and my fellow workers. Today, however, I feel distanced from my colleagues and uneasy in their presence. As someone with a ready opinion, I am having to hold my tongue when engaging with colleagues. This is not the brave and innovative world I want.

The UK needs change. I have no regrets about voting Brexit, but I do hope that the dust will settle soon and that the City will once again show itself at its best. Meanwhile, this younger generation of bankers needs to stop and take stock: don't feed your critics by acting as petty minded, self interested, spoilt children of the Millennium.

Seamus James is the pseudonym of a senior finance professional who's worked in infrastructure roles in the City since the late 1980s.