Always lock your door from the inside! Otherwise someone will surely enter your room for whatever reason (the maid, someone misreading his room number, some hooker trying to earn some additional money, an FA for the same reason sans money etc).
And of course EU-OPS FDT limits are so bad that simply rostering to the limit will surely cause fatigue. At the end of last summer nearly everyone in my company fell asleep during a flight more often than not. A result of p**s-poor rostering.