If you have 3 or more of the following dozen delusions:
1) Commercial banks are an essential part of the modern economy. Their rescue during the Global Financial Crisis, at extraordinary cost to the taxpayer, was unavoidable.
2) Central banks are required to fight inflation and protect against financial instability.
3) Economists and financial theorists know what they're talking about.
4) Fund managers represent smart money. They help marshal capital worldwide to where it can earn the best returns.
5) Bonds are safe assets that rightly form the cornerstone of long-term savings schemes.
6) Cheap big market index funds (like S&P500 or FTSE 100) provides the best return for small investor.
7) The stock market always rises over the long term and is therefore the best place for your savings over the long run.
8) Economy with fiat money cannot collapse.
9) The financial media exist to help investors make sense of the capital markets. (SDS: Hmm... the author doesn't count SA probably).
10) Value investing will keep premium in next decade(s).
11) Hedge fund managers still offer sophisticated clients something different from traditional asset managers.
12) Gold is a barbarous relic.
but consider yourself as a serious investor you should read the book "Investing Through the Looking Glass" written by Tim Price.
The author spent about 75% of the book to explain roots and outcomes of these delusions and about 20% of the book to possible solutions (not unquestioned). Remaining ~ 5% of the book is
condensed modern investor's manifesto which it worth to read if you don't have time for whole book. This book should NOT be in the first dozen books about investing you read (it is quite far from 101 course for beginners) but most of experienced investors should read this well-written book.