Granted, but In my experience, old-network ties are ever-lasting.
Certainly when it comes to knowing a friend of a friend in a legal, banking or footballing sphere.
My son has an old-boy network at his grammar school - old gits who went to the school for just a few years but join up each year to chew the fat and call in favours and cash.
I've done it throughout my own career. Couple years here, someone knows someone, they are vouched for, before you know it, someone you hardly know has removed an obstacle for you.
Way of the world, sadly.