Class 10 son put a 'Do not disturb' sign on his door. Six snack trips since 7 pm
Hand-lettered, taped at eye level, "Exams. Do not disturb". Since 7 he has come out for biscuits, a banana, the charger, chai, "just checking something" and more biscuits. I'm the on-call one this week, so I'm in no position to judge anyone's concentration.