Humans often learn about the world by observing, imitating, and receiving explicit instruction from others. Even when learning via trial-and-error or reflection, human adults often do so immersed in a relevant context. But what happens when most of this scaffolding is removed? How effectively can humans bootstrap learning in an information- and context impoverished environment? In eight pre-registered experiments, we sought to understand how effectively humans learn from ‘zero’ in a series of simple stimulus recognition tasks that subjects easily learned when provided with explicit instructions. When no explicit guidance was provided, fewer than half of the subjects learned the task despite receiving trial-by-trial feedback and monetary reward. Surprisingly, providing partial, explicit instructions about the structure of the task—a ubiquitous pedagogical approach—did not improve performance nor reduce individual variability. Instead, explicit instructions that constrained the action space (i.e., valid key presses) partially recovered performance but still pointed to action inhibition as particularly challenging to learn without explicit instructions. Our results suggest that individual differences emerge in impoverished environments without reflecting underlying capacity, and that a major driver of learning, even for the simplest of tasks, is a combination of luck and the nature and quality of scaffolding available to the learner.