On resonance, frequencies and wavelength

According to wikipedia, resonance is the tendency of a system to oscillate with larger amplitude at some frequencies than at others.

One familiar example is a playground swing, which acts as a pendulum. Pushing a person in a swing in time with the natural interval of the swing (its resonant frequency) will make the swing go higher and higher (maximum amplitude), while attempts to push the swing at a faster or slower tempo will result in smaller arcs.

Which means resonance happens when two waves of same or different wavelength act upon each other in such a way that one wave supports the other to reach the maximum amplitude.

This also applies to human thoughts and feelings. Two people are said to have good wavelength or lambda when their wavelength helps each other to achieve the resonance resulting in larger magnitude of happiness.