My thoughts are that if you didn’t make friendships or useful acquaintances during college then it’s probably down first and foremost to your personality type and how your classes were scheduled. But first and foremost, your personality.
You seem to be hung up on the myth of college as “that special experience” but it’s just a myth. If you happen to be just somewhat on the introvert side and your schedule mixed you up with different people for every course you were taking, good luck forging any long lasting relationships. You can socialise, of course, but if you don’t share the time consistently with people then it’s going to be about as long lasting as acquaintances you make on the elevator or the bus.
You will probably find you start networking much better once you get a job, simply because you will be spending time consistently with a limited amount of people.
T0RB1T