Its strange because i found the exact same thing, I performed reality checking through the day, but it was very rarely a reality check that gave me lucidity. I just realise im dreaming, no particular reason for it.
I occasionaly reality check just to get rid of the apprehension of lets say, jumping off a large building for instance. Sometimes lucid dreams can be too real, the concrete looks sooo hard, and its such a long drop, you start thinking, what if im not actually dreaming..

Saying this reality checking definitely made a difference to me, if not just to keep my mind on lucid dreaming through the day.