Question

1A-1: I don't understand how completing the square of x^2 - 2x -1 results in (x-1)^2 - 2

When I did the algebra it went something like..

y = x^2 - 2x - 1
Find perfect square:
y = (x - 1)^2
y = x^2 - 2x + 2
y = x^2 - 2x + 2 - 3 (equivalent to original equation)

y = (x - 1)^2 - 3

Can't believe I got the first question wrong T_T, someone please help