Final answer:
Internal distractions include stress, personal worries, ADHD, and the lack of effective study habits; all can impede concentration and metacognition.
Step-by-step explanation:
Common internal distractions that can make it hard to concentrate include stress, anxiousness, and excessive worry about other life responsibilities, such as financial security or family obligations. These distractions impact our ability to engage in rational, focused thought, leading to errors and diminishing our capacity for metacognition. The presence of conditions such as ADHD can further aggravate the ability to concentrate, making students more prone to frustration and distracted by even minor disruptions. Making good study habits a priority, such as preparing your reading space to minimize distractions, can significantly enhance focus and enable more effective learning.