How is getStorageAt() used?

Question

I have tested with eth.getStorageAt() and it shows what I think is 32 bytes of storage. But what is the point of this function? Are we meant to see unused space with it?

This is what I have:

> con
{
  abi: [{
  constant: true,
  inputs: [],
  name: "studentAge",
  outputs: [{...}],
  payable: false,
  stateMutability: "view",
  type: "function"
  }, {
  constant: false,
  inputs: [{...}],
  name: "setAge",
  outputs: [],
  payable: false,
  stateMutability: "nonpayable",
  type: "function"
  }, {
  anonymous: false,
  inputs: [{...}],
  name: "changedAge",
  type: "event"
 }],
 address: "0xa6b4017e8437ace3301f9751735e84836cfc0b21",
 transactionHash: null,
 allEvents: function(),
 changedAge: function(),
 setAge: function(),
 studentAge: function()
}
> eth.getStorageAt(con.address,0)
"0x000000000000000000000000000000000000000000000000000000000000002d"
> eth.getStorageAt(con.address,1)
"0x0000000000000000000000000000000000000000000000000000000000000000"
> 

Code:

pragma solidity ^0.4.18;
contract CollegeAdmin {
uint public studentAge=18;
event changedAge(uint age);
function setAge(uint age) public { 
studentAge = age;
changedAge(age);
}
}