Italy and Spain are extreme cases of low fertility linked to postponement of childbearing. Demographers continue to debate causes of postponement. This qualitative study was designed to contribute, by purposively selecting Italian and Spanish women in different socio-economic circumstances who are partnered, childless and aged 30 to 35. Most want children but “not now” or are deferring the decision whether to have children. Their different circumstances inflect explanations of postponement in a language of choice, either “taking time” to achieve other goals or “holding on” for conditions to change. They are encouraged to postpone by optimism about their capacity to conceive, flexible norms about “the right age,” prolonged dependence on their parents, the normative salience of “total motherhood,” and family-unfriendly, gender-unequal workplaces. Elements of competing demographic theories often coexist in interviewees’ accounts. The ‘desire-intentions-behaviour gap’ does not always capture their flow or complexity.