I mean like if we consider the characteristic impedance as a lumped resistance, say Z0, now the load Rs=Z0, as its perfectly matched; so applying a simple voltage divider for series resistances, now does this mean anytime we send a signal on a transmission line, say a PCB trace, only half the signal is going to reach the load? i.e., if we send a 5Vp-p square wave on the line, the signal received at the load is going to be 2.5Vp-p and we need plan our source signals accordingly?