Patterns patterns everywhere if we have the time to look.
And I have seen mothers going through the grocery store showing their infants various items and discussing each with them. I have also seen others look at them pityingly, obviously thinking they were nuts to carry on such conversations with an infant. But these are the conversations that brain tissue growth is made of! And these mothers are intuitively doing the right thing.
There are a million household objects and inexpensive toys (soft rubber or cloth balls, blocks, dolls etc. which can be placed within the grasp and gaze of infants to stimulate them.
Of course, the caretaker (mom/dad) must be attending closely, like a referee at a wrestling match, to see that they are within reach but are not a danger to the child.