I didn't do that either, but I know many who did and for the same reason - supposedly it helped the baby sleep. I think that's a myth. Solid food is not recommended before 6 months (or used to be 6 months anyway) because an infant's digestive system is not able to handle solid food such as cereal in the milk.

Babies aren't on our schedule, they are on their own schedule, and it's up to us to adjust - not them.