What’s something you learned that completely changed how you saw everything?

I’ll start:
When I found out that being healthy and losing weight wasn’t about spending hours exercising & running miles every day, but that 90% of the battle was just about removing horrifically unhealthy (and very normalized) chemical substitute, grain heavy, “fat free”, and sugar packed foods - but was just about getting back to the basics and animal based fats. Everything else is crazy easy after you do that.

Then to add, that your mood, depression, energy levels, are also SO insanely dependent on that same problem. 

What was one of yours?