Is protein folding deceptively simple? The complexity of the energy landscape of proteins leads in many cases to heterogeneous folding reactions, which defy observation by standard ensemble techniques.This lecture will show, using several recent examples from my lab, how FRET experiments on individual molecules diffusing in solution or immobilized within lipid vesicles can shed new light on complex folding dynamics.In particular, it will be shown that several folding pathways can exist even in a small "two-state" folder, let alone in a larger multi-domain protein [1].I will also discuss a case where the folded state, thought to be fixed in structure, is in fact rather elastic.