Simple. You eat something once, you like it so much that you want to eat it again. Not always that easy with kids, sometimes they require many tastes. In fact, and I may have said this before, it may take as many as 12 tastes (or more) of a particular food before your child will come to accept it and like it. If you persist, it can and will happen.
Take the case of Izzy and toast. I love toast for breakfast. As soon as Izzy was old enough, I would put toast out for him with whatever he had for his morning meal. At first he would pick it up, examine it, nibble and put it down. Sometimes he would fling it down. He did not seem particularly keen on it.
How could my child not eat toast? It was a staple of my diet. I would not give up. I put that toast out day in and day out. Country bread, mixed grain slices, day-old baguettes all made their way to Izzy's plate. Finally, more bites were taken. Months passed and then he just started to eat it, and get this, he sometimes even eats the crusts!!
Now on some mornings toast is all he wants for breakfast.