I only ask as so many people seem to moan they are kept awake by the slightest thing...I have NEVER been woken up by neighbours, and have only had very slight difficulties in going to sleep (completely sober, may I add) in a house where there is a loud party going on downstairs. The only time I am kept awake by noise is if I am worried DP is making enough noise to disturb the neighbours (although we have never had a complaint so maybe they are the same as me) DD is the same, she will happily sleep through any noise. The only noise that will wake me, weirdly, is DD crying. Must be some kind of instinct.
I'm pretty sure it is in the upbringing, eg as a baby I used to have my naps in brass band practises and went camping nearly every weekend so got used to other peoples "living sounds". We have never tiptoed around DD when she is asleep, and have made sure she isn't fussy about where she goes to sleep, so she will happily sleep almost anywhere, which means a lot more freedom for us and her. She has had naps in the middle of parties, at football matches and while people do DIY, and I bet she will have no trouble coping with sleeping in university halls or wherever.
Am I just really lucky with my sleep genes or are some people just too fussy?