Senioritis is Inaction
For me, senioritis is inaction more than action -- I'm not doing some goated side project or biking for 10 miles a day; I'm instead just sitting in my room shuffling tabs around (and weapons on survev.io (with the t key ;))) and slowly wondering when the time I had at the start of the day left me. Perhaps it's because I spent too much time on commitments (Boy Scouts, Robotics, Trumpet, more Robotics), but I generally feel drained and tired showing up to school, performing at school (unless we're doing something cool), and really only feel alive when I'm doing good work at night.
Maybe it's just that time of year....