The most potent drug - Nostalgia
I just had a nostalgic moment in my exam hall. It was so quiet except for the sound of the ceiling fan and people's footsteps outside. I was looking at the wall clock 45 minutes into my exam (that's what I do in exam halls). This particular time, it brought back memories of my childhood (like in 5th or 6th grade) when I used to play Monopoly with my friends during power cuts.
Another memory that recently surfaced depicted my school at 3:30 PM when classes would be over, and there would be clamoring in the corridor until we went to the parking lot. This was triggered by people chatting in front of the exam halls. There is a certain comfort in these noises.
Savor these moments when they happen, but don't be jailed by them. Remember, time is a cruel mistress who will make you forget the struggles and just remember the good parts.
It's like what Andy says in The Office: "I wish there was a way to know you're in the good old days before you've actually left them."