The biggest mistake people make is focusing on income while ignoring everything that income has to pay for. Most conversations about money revolve around salaries because salaries are easy to compare. The problem is that two people earning exactly the same amount can end up in completely different financial positions depending on their expenses.

A person earning £5000 per month who spends £4800 will feel very different from somebody earning the same amount and spending £3500. From the outside, both people appear equally successful because nobody sees the invisible side of their finances. Most people only see the income and assume the rest of the picture looks just as good.

The result is that people often overestimate how financially comfortable higher earners really are.

One of the reasons this happens is because expensive living slowly becomes normal. Nobody suddenly wakes up and decides to dramatically increase their spending. Instead, the process happens gradually over several years. A slightly nicer apartment becomes affordable, eating out becomes more frequent and paying for convenience becomes easier to justify.

London has a unique ability to make expensive behaviour feel completely ordinary. Spending £15 on lunch barely raises eyebrows. Paying £7 for a pint feels normal in many areas. A quick weekend abroad can cost hundreds of pounds before you've even arrived at the airport. None of these expenses feel outrageous because everybody around you seems to be doing exactly the same thing.

Eventually, a lifestyle that once felt luxurious starts feeling average. Income increases, spending increases and many people are left wondering why they don't feel significantly better off despite earning more money than ever before.

The people who eventually become financially comfortable usually understand something that most people overlook. A higher salary is helpful, but keeping more of that salary is equally important. Financial progress is rarely determined by income alone. It's usually determined by how much of that income survives after your lifestyle has been paid for.

This doesn't mean enjoying your money or refusing to spend on things you value. It simply means recognising that every increase in income doesn't need to be matched by an increase in spending. The gap between what you earn and what you spend is where savings grow, investments grow, and financial security begins to take shape.

The interesting thing is that this part of personal finance is almost completely invisible. Nobody notices it, but it often makes the biggest difference over time.

For years, I assumed that earning more money would solve most financial problems. I thought there would be a salary where everything suddenly felt comfortable and financial stress largely disappeared. The more I've learned about money, the more I've realised that the number itself is rarely the solution.

I've seen people earning impressive salaries who constantly complain about money, and I've seen people earning far less who seem perfectly comfortable. The difference is usually what happens after payday. One person keeps more of what they earn while the other gradually allows their lifestyle to absorb every increase in income.

Let's look at somebody earning roughly £5000 per month after tax. Rent alone could easily cost £2000 in many parts of London. Add council tax, utilities, transport and groceries and a large percentage of that income has already disappeared before any saving or investing has taken place.

The surprising part is that none of these expenses are particularly extravagant. There are no luxury cars, private members clubs or designer shopping sprees involved. It's simply the cost of maintaining a fairly normal lifestyle in one of the most expensive cities in Europe.

That's why so many people earning good money still feel financially stretched. The issue isn't that they're earning too little. The issue is that ordinary life has become remarkably expensive.

Don't assume a higher salary automatically creates wealth. Many people spend years chasing income targets only to discover that their lifestyle expanded alongside their earnings. More money arrived, but very little changed underneath the surface.

It's also important not to compare yourself to people who appear successful online. Social media is extremely good at displaying spending and extremely bad at displaying savings, debt and financial reality. The visible parts of somebody's financial life rarely tell the full story.

Most people are wealthier than they look or poorer than they look. It's surprisingly difficult to tell which is which.