Thanks marcellus
I think I do vaguely remember reading something about babies being on three meals of solids a day by 7 months... Mmm, can't quite remember where I read that. It just seems so quick to be on 3 meals a day when he only started on solids at just before 6 months.
It's only been in the past week that (like you said) something has 'clicked' with DS, and he seems to be getting really excited (and impatient, lol) about getting his food.