That's the delta-V to get away from Earth, and 90% of it is spent shifting from a circular low orbit into a transfer/escape orbit. When you're coming back, you

That's the delta-V to get away from Earth, and 90% of it is spent shifting from a circular low orbit into a transfer/escape orbit. When you're coming back, you don't need to spend that energy. Instead you slightly adjust your aim so your transfer orbit hits the atmosphere instead of missing it.