C Dynamic List Troubles

C Dynamic List Troubles

typedef struct {
long blarg;
} item;
typedef struct
{
item* items;
int size;
} list;
List and Item structs, fairly simple.
list l;
l.size = 3;
realloc(l.items, l.size*sizeof(item));
Create a list, allocate it to hold 3 items.
item thing;
item thing2;
item thing3;
thing.blarg = 1337;
thing2.blarg = 33;
thing3.blarg = 123;
l.items[0] = thing;
l.items[sizeof(item)+1] = thing2;
l.items[(sizeof(item)*2)+1] = thing3;
Create some items and add them to the list... but when printing them:
printf("List 0: %ld\n", l.items[0].blarg);
printf("List 1: %ld\n", l.items[sizeof(item)+1].blarg);
printf("List 2: %ld\n", l.items[(sizeof(item)*2)+2].blarg);
> List 0: 1337
> List 1: 33 {
> List 2: 1953720652 !
Where did it all go wrong?