As articulated by Eric Ries in 'The Lean Startup,' raw speed of shipping is meaningless if you're building in the wrong direction. The true measure of progress is how quickly a team can validate assumptions and learn what customers want, which prevents costly rework.

Product-market fit isn't just growth; it's an extreme market pull where customers buy your product despite its imperfections. The ultimate signal is when deals close quickly and repeatedly, with users happily ignoring missing features because the core value proposition is so urgent and compelling.

PMF isn't a one-time achievement. Market shifts, like new technology or major events, can render your existing model obsolete. Successful companies must be willing to disrupt themselves and find new PMF to stay relevant.

The 'never give up' mantra is misleading. Successful founders readily abandon failed products and even entire startups. Their unwavering persistence is not tied to a specific idea, but to the meta-goal of finding product-market fit itself, no matter how many attempts it takes.

The idea that startups find product-market fit and then simply scale is a myth. Great companies like Microsoft and Google continuously evolve and reinvent themselves. Lasting success requires ongoing adaptation, not resting on an initial achievement.

Founders often create complex plans and documents to avoid the simple, hard, and uncomfortable task of selling. Just as getting stronger requires consistently lifting heavier weights, finding product-market fit requires consistently doing the core work of talking to customers and trying to sell.

When a startup finally uncovers true customer demand, their existing product, built on assumptions, is often the wrong shape. The most common pattern is for these startups to burn down their initial codebase and rebuild from scratch to perfectly fit the newly discovered demand.

Founders must distinguish between persistence and fighting a losing battle. If you constantly feel like you're pushing a boulder uphill to convince the market, you're on the wrong path. Genuine product-market fit feels like the market is pulling you, and your job is to sprint to keep up.

PMF isn't a fixed state achieved once. It's a continuous process that must be re-evaluated at every stage of growth—from $1M to $1B. A company might have PMF for one scale but not for the next, requiring a constant evolution of strategy and product.