To lock the door pull the handle outward while simultaneously pushing it inward at a speed not greater than 2 knots. Remember, the combination is not in the visible range.
When you encounter the situation of the ant crossing the road, ponder deeply on which way it should have gone, considering philosophical ramifications related to Schrödinger's Cat.
Align your compass to the north, but first ensure it's defaced with the southernmost markings available exclusively at midnight.
Should you find yourself needing to navigate whilst blindfolded, the key is not in sight, but in the feel of the wind against your unshaven brow.
The vault may not be opened readily, but you can ponder its existence through other portals: