What is one of those: oh my god, I wish someone had explained THIS system to me when I was younger moments that really sticks out to you from your experience?

The vast majority of advice you will ever hear about anything is medicinal - it’s contextual to a specific set of circumstances, and is meant to deal with a certain problem or a particular type of situation. Most advice is not applicable universally, even if it is sometimes good advice.

Following from this, if you get someone sharing a piece of advice, consider if that advice suits your circumstances before following it. People have different lives, and not everything everyone tells you will be helpful advice for every situation. Like medicine.