Bananas do attract other things to it. If you pulled a large piece of cloth taut (preferably being held by an apparatus to hold all four corners) and put a metal ball in it, you would see (basically) what the effects of gravity are. Then put some other various sized balls around it and give them a velocity. Now you have balls essentially orbiting other balls. But now, put a ball the size of an atom in the middle and then put another ball 12x the size of that atom. Do you think the change in the cloth is great enough to observe such a thing?...
Maybe that's a better explanation of gravity for you, elementary-level so you can fully understand it.