I can walk down a Bangkok street in my suit and be comfortable. Why? Lightweight Italian wool fabric, silk-lined jacket, cotton shirt. Meanwhile the guy next to me in short sleeve polo and jeans is a puddle of sweat.

Synthetics definitely have their place. Uniqlo's Airism is a game-changer in the tropics and lots of outdoors activities like hiking or skiing are much more comfortable with modern technical fabrics, but natural fibres are far from obsolete.