Is there a financial decision that most of the people make in their twenties that has the most significant long term compounding effect - positive or negative - and that people only fully understand once the compounding has already done most of its work?
The decisions that matter most financially tend not to feel like major decisions at the time - the extra super contribution that gets set up and forgotten, the credit card debt that gets carried for three years longer than it should, the salary negotiation that doesn't happen and sets a base that all future increases build on. Would love to know what people here think falls into that category based on what they've seen in their own financial life or in the people around them and whether understanding it earlier would have changed anything or whether it's the kind of thing that can only be seen clearly in hindsight.