Language is a hallmark of the human species; the flexibility and unbounded expressivity of our linguistic abilities is unique in the biological world. To understand this astonishing phenomenon, we must consider how language is created: moment by moment, in the production and comprehension of individual utterances; year by year, as new language learners acquire language skills; and generation by generation, as languages change, split, and fuse through the processes of cultural evolution. In this talk, I discuss how a fundamental constraint—the Now-or-Never bottleneck—impacts language across these different timescales. During normal linguistic interaction, we are faced with an immense challenge by the combined effects of rapid input, short-lived sensory memory, and severely limited sequence memory. To overcome this bottleneck, language users must learn to compress and recode language input as rapidly as possible into increasingly more abstract levels of linguistic representation. This perspective has profound implications for the nature of language processing, acquisition, and evolution. To illustrate, I present results from lab-based cultural evolution experiments, computational simulations of language acquisition, and psycholinguistic experimentation, highlighting chunking as fundamental to our language ability.