Human attention is subject to fluctuations. Mind-wandering (MW) - attending to thoughts unrelated to the current task demands - is considered a ubiquitous experience. According to the Control Failure x Concerns view (McVay & Kane, 2010), MW is curbed by executive control, and task-irrelevant thoughts enter consciousness due to attentional control lapses. The generation of off-task thoughts is assumed to increase with higher number of personal concerns. Challenging this view, older adults report less MW than younger adults. Here, we addressed the hypothesis that older adults report less MW due to a lower ability to notice attention lapses and to appraise their current on-task focus. In an age-comparative study (N = 40 younger and N = 44 older adults) using a battery of three tasks spanning working memory, reading comprehension, and sustained attention, we assessed the correlation between the degree of self-reported on-task focus and task performance on a trial-by-trial basis. Younger and older adults' degree of on-task attention measured through thought probes was correlated equally strongly with performance across trials in all tasks, indicating preserved ability to monitor attentional fluctuations in healthy aging. Self-reported current concerns' number and importance did not differ across age, and they did not predict self-reported attention across tasks. Our study shows that lower rates of MW in aging do not reflect lower validity of older adults' attentional appraisal or lower levels of current concerns.