Working at a nursery, a common question is "can I grow this indoors?" Usually the plant in the customer's hands is something like a florists' hydrangea, miniature rose or chrysanthemum. Sometimes it's even a dwarf lemon; often it's a potted succulent.
Almost universally, my answer is "no, not for long, it needs to be outdoors in the sunlight and fresh air."
Customers often either don't like that answer or don't believe. Often the ensuing conversation continues with "why?"
I usually say something like, "There are a lot of differences between indoors and outdoors. First, there isn't enough light indoors, but there's also a lack of air circulation and adequate humidity inside a home."
Customers, God bless them, usually pick up on the first comment about a lack of light and respond with something like, "Oh, I have a really bright room and it has lots of windows and light; I'm sure it will get enough light."