50 years of sales: What I didn’t learn in school

26 February 2026 · Markku Tauriainen

After five decades in the field, I’ve realized that the most vital sales lessons aren't found in textbooks. Success is built on human psychology and the resilience of the mind.

I’ve been in sales for a long time — long enough to see trends come and go, industries shift, and “new” sales advice repeat itself every decade with a different label. And if there’s one thing I’ve learned after 50 years, it’s this: the most important lessons in sales aren’t taught in school. Not because school is useless, but because sales is less about theory and more about people — how they think, how they feel, how they hesitate, and what makes them trust. This article is a reflection on the real lessons that shaped my results over the years — the ones learned through conversations, rejection, and experience, not textbooks.