the only reson this MIGHT happen is by touching your previouse self you would disrupt the time line in some way... as far as the same matter ocupying the same space.. no because if it is life your talking about a human being is suposidly sheds all his cells (exluding a few special ones ) and grows new ones in the course of 7 years so in 7 years you are touching a new person but even assuming you brought a rock back and touched it with its earlier version there is nothing to suggest anything would happen even thou you have a group of atoms identical in shape and in nearly every way they still would have no reaction!
I once wondered if an object from the future touched it's self in the past if the effects might be similar to matter touching anti-matter. But, I agree that nothing would happen out of the ordinary since it would simply be matter touching matter like identical twins.