Why does my brain wander mid-task no matter how hard I try?

Sustained attention is not powered by effort alone. In ADHD, working memory limits, internal distractions, and fatigue cause attention to drift even when motivation is high. Trying harder often increases mental strain and worsens focus. Clinicians emphasize that attention fluctuates based on stimulation, interest, and load. External supports, frequent breaks, and task variation are more effective than forcing concentration. Attention drift is not a failure of willpower.