Recent studies in cognitive psychology have challenged the traditional view that multitasking enhances productivity. Researchers argue that the human brain is not designed to process multiple streams of information simultaneously; instead, it rapidly switches attention between tasks, leading to a phenomenon known as 'attention residue.' This residue impairs performance on subsequent tasks, as lingering thoughts from the previous activity reduce cognitive focus. Furthermore, neuroimaging data reveal that task-switching activates the prefrontal cortex more intensely than focused work, resulting in higher mental fatigue and increased error rates. While some individuals claim to be proficient multitaskers, empirical evidence suggests that they are often less accurate and slower than their focused counterparts. Consequently, experts advocate for 'single-tasking' in academic and professional settings, emphasizing that deep concentration fosters higher-quality output and better retention of information. These findings have significant implications for how students should structure their study habits, particularly in an era of constant digital distractions.