I once received this question at a job interview: what have you changed your mind about in the last decade? I thought it was a good question then and it remains a good question now.

At the interview, some 15 years ago at a funds management firm, I answered I was convinced that a concentrated investment portfolio was a key ingredient to being a successful investor. Previously, I hadn't been convinced of that.

I was being a bit disingenuous because I knew that this answer would be music to this fund manager's ears. But I also happened to believe it, which certainly helped the cause.

Today, I would take issue with my former self; I would take issue with the answer I gave back then.

But let's back up a bit and explain why I gave that initial answer. It probably had deep roots. All the way back to my childhood, in fact. As a kid, I remember seeing a lot of issues in black and white. Right and wrong, good and bad, win and lose, and so on. There wasn't much room for shades of gray. And being somewhat of a stubborn child didn't help either.

When I got my first job in finance as an analyst at a sell-side broker, I was encouraged by my employer to take strong views on stocks and sectors of which I had coverage. The company didn't take kindly to 'hold' recommendations on stocks; 'buy' and 'sell' recommendations were more appreciated as they generated more trading and brokerage fees for this firm!

I carried this type of thinking over when I became an equities portfolio manager, and indeed with my personal investing. It was about having strong views on a small bunch of stocks.

My investment heroes back then all had concentrated portfolios, who's virtues they proselytised. The likes of Erik Metanomski in Australia and Warren Buffett and Mohnish Pabrai overseas.

What's changed over the past decade then? Losing some money during the GFC had an impact, no doubt. But it's much more than that.

I've changed my approach to investing because I've changed my approach to life. I've realised most issues aren't black or white. I've realised how much I don't know about many issues. I've realised that I'm more risk-adverse than the average person about lots of things. I've realised that I don't like the stress involved in taking a big bet. All of this has made me an advocate of having a diverse investment portfolio.

I'm not saying that concentrated investing can't work. It can. If you are a good investor, with the stomach to take volatility and potentially big drawdowns, then a concentrated portfolio can do wonders. It just doesn't work for me.

What have you changed your mind about in the last decade? I'd love to hear your thoughts.

In this week's edition ...

The FTX saga has a bit of everything. Knowing America, books and movies on the subject will already be in the offing. For Australian investors, it might seem the drama is too movie-like to have any relevance to them. Yet there are many lessons to take away from FTX - some obvious; others not-so-obvious.

Jody Jonsson of Capital Group believes investors need to reset their expectations about how a typical investing environment looks. She identifies five seismic shifts happening in economies and markets and the investment implications for each.

Superannuation has become a political football and there's noise around further changes to the system. Former Chair of Retirement Income at Challenger, Jeremy Cooper, says we need to take a deep breath: while super isn't perfect, more changes could add further complexity to a system that's served us well.

Meanwhile, the rules for eligibility to contribute to super are relatively simple but there are additional conditions regarding access to the bring forward rule that may result in unintended tax consequences. Julie Steed looks at the rules and reviews what happens when they are not fully met.

Retirement has become a central part of the conversation about the future of super. As more post-retirement members have more superannuation savings than ever before, Andrew Boal and Steve Freeborn of Deloitte believe the time has come to better engage with people about managing their retirement needs.

A sharp spike in bond yields has resulted in Australian Real Estate Investment Trusts being among the poorest performers on the ASX this year. With the RBA prioritising growth over inflation though, A-REITs may be set for a turnaround, according to Cameron McCormack.

Private credit - loaning money to private businesses including SMEs - is booming and investors can now get direct access to funds in the space. Roger Montgomery is our guide to the benefits and pitfalls of investing in private credit.

This week's White Paper comes from Vanguard Investments, whose latest quarterly ETF report highlights that despite the market pullback, Australian ETFs are still attracting substantial inflows.