Plainly it isn't an exact science, despite it being a complex interaction of micro-decisions and corresponding thought; perhaps it doesn't always work and we pass by some potential soulmates like the proverbial ships in the night, never quite connecting. Then again, perhaps the system is tenacious and continues to run like a computer program on infinite loop, so that if at first you don't meet, you are drawn back together for another try.
Nerd Do Well: A Small Boy's Journey to Becoming a Big Kid (ed. Penguin, 2011) - ISBN: 9781101529089