I was wondering the same thing...
Maybe this could be a part of a conversation where two people discuss how they cook a certain recipe. One of them would say I don't put onions in the salad, because "reasons" (Εγώ δεν βάζω κρεμμύδια στην σαλάτα, επειδή ...). The other one could reply Εγώ βάζω.
Another possibility would be when a child who is just learning how to speak wants to make sure that his/her parents will allow him/her to put the thing where it needs to be.