A sack of salt.

When I was serving mandatory military service, the Sargeant told us something like "you'll only know someone after you ate a sack of salt". At 5g a day, a sack being 60kg, that would be almost 33 years.

Hall determined that it takes about 50 hours to evolve from an acquaintance to a casual friend, 90 hours to transition to a friend and more than 200 hours to become a close friend.

Important for me to remember... patience