No one knows, and they just stop when they need to stop. People tend to stop because they already tired of searching or they already searching for so long. To meet with special one, you need to stop (searching) and begin to love (someone). Love the people who you able count on such as your best friend. Your best friend has a higher chance to become your Soul mate/The one/Special person/True love compare to a nameless stranger you will meet in the future.
SmiileURGorgeous