>>7625807They don't. You are also in a quantum state, and as soon as you are in a position where your subjective experience is conditioned on the state of the electron, you become entangled with it.
Because you are a very large object, the state rapidly decoheres, and so now the states "Electron goes through slit 1 and you experience an electron going through slit 1" and "Electron goes through 2, you experience it going through 2" are separate and do not interfere, rendering it definitely.