Why did distance form to begin with? That could give you a clue as to why things didn't go back to what previous level of comfort you wanted to have back instantly.

When you start to reconnect with someone, things very very rarely go instantly back to how they were. It's often like starting over with someone new, with the awkwardness of past memories and the knowledge of what caused the drift to begin with.

It sounds like this was how it was for your old aquaintance, yet you were pushing towards the level of friendship that is in the past? Which would increase the awkwardness most likely as your old aquaintance wouldn't be feeling that level of closeness and might not have known how to respond to it.