If f = 0, the capacitor looks like a gap/dead end to the source, so the whole voltage is across the capacitor. If f were infinite, the capacitor would look like a wire, and the whole voltage would be across the resistor.
This is a simple way to memorize RC filters.
It doesn't account for non-ideal components in reality. Capacitors have parasitic properties.
LR filters work the opposite way: at low frequencies, a coil is basically just a conductor, while at infinitely high frequencies, a coil behaves like an open circuit.
