A wave packet is formed when a multitude of sine waves of different periods are linearly added. This localizes the pdf, and hence creates certainty in a particle's position. However, basic sinusoidal functions are cyclical, hence the additton of two sinusoidal functions are always cyclical. Doesnt this imply that with the addition of multiple sine waves, we would expect to see wave packets at regular intervals of space? How do they produce a "lone" wave packet?