insert() but with negative index

[naughtysensei]

Inserting items with non-negative index gives expected results:

num = [1, 2, 3]
num.insert(0, "min")
print(num)

Output:
['min', 1, 2, 3]

but with negative index, as in this case shouldn't "max" be inserted at last index

num.insert(-1, "max")
print(num)

Output:
['min', 1, 2, 'max', 3]

I mean its not wrong its how they made python to work but why would they do so or am being stupid here?