The presence of data on life courses and places of schooling, but also data of a more subjective kind on “personal experience”, shed light on the measurement of skills in the 2004 “Information and Daily Life” Survey (Information et Vie Quotidienne: IVQ). Of the total 9,733 respondents who were schooled in French (whether in France or abroad), 5% are severely challenged in one of the three basic skills relating to written texts (reading, comprehension, and writing), 5% are significantly challenged, and 7% moderately so. Among the diverse factors involved in the individual trajectories of people experiencing relatively severe functional illiteracy, the lack of reading habits in the childhood family environment is especially conspicuous. Moreover, respondents who are conscious of their difficulties generally became aware of them at the outset of their schooling. This corroborates the hypothesis of a flaw in the learning process, with respondents having stayed in school for better or worse, their education history marked by class repetitions and school transfers. Another major category of explanatory factors consists of childhood events. In particular, sibling death and violence experienced at school have an adverse influence on basic learning. Unexpectedly, respondents reporting that one of their parents underwent a long unemployment spell during their childhood are far less likely to have major problems in handling written texts.