Sleep-deprivation isn't just for parents of newborns, I'm still waiting for my 5 year old, Oliver to sleep through the night, every night. Really.
Both he and Alexander are light sleepers like their Mama and both will usually wake up at least once a night if not more. Good times.
...And it's not just us who are suffering, the majority of parents I've asked recently, seem to be too. It appears we are all relentlessly searching for the holy grail of consistent sleep-argh remember the full 8 hours pre-kids. It's but a distant memory for myself and so many.