I found this to be a bit strange. Can anyone explain to me: Why, if I have a list like this:

```
l = [1, 2, 3, 4, 5]

```

and I do this reassignment:

```
l[-1:0] = [99,]

```

then it inserts the 99 to the left of the 5, like so:

```
[1, 2, 3, 4, 99, 5]

```

We must assign to an iterable `[99,]`, assigning to just the integer `99` will give an error, which might be a clue as to what's happening here... I guess?