Not a pilot, but I have stood reactor watches on a nuclear powered cruiser. The second most boring watches were on those steady steaming trans-pacific trips. For days on end, nothing changed. For four hours, the throttle man did not touch the throttle. Reactor power, delta-t, pressure, rod height, all the same. Go off watch and return eight hours later, the same as you left. There was nothing to do.
Boredom for the watch standers was interrupted every fifteen minutes, when you had to record the readings from every instrument on the control panel. This kept you busy and the others busy as they did the same for their watch stations.
The killer watch, was the shutdown, cold iron watches. Just you in the control room, and a machinist in the engine room. Eight hours of silence, no change, alone with nothing to do but take instrument readings every fifteen minutes. If not for that, you would certainly fall asleep.
What concerns me is the one hour and 18 minutes the flight was out of contact with air traffic controllers, and then the fact the plane had left it's flight plan. Yes, I know there was a call to air defense, and fighters were readied for intercept, but 78 minutes of dead air from an Airbus 320 seems like a long stretch without serious action having been taken sooner.