The best bit of advice I ever got on this was from a coach who would always introduce heavy lifting days with the phrase “be ambitious, but not greedy.” That so clearly summarizes the mindset that makes progress but avoids injury. You want to work hard, do the difficult work of improvement, but do so in an honest, humble way. Greedy exercise involves taking our abilities for granted and letting our ego make decisions for us. it is recovering from lifting weights that makes you stronger. This is a subtle but essential distinction to make.