Josh can't believe it: Sydney Mills asked for his number. His mind jumps quickly to their future house and kids.
He sits by his phone and waits. Nothing. After a few minutes he grabs the cordless phone and goes across the street to the park.
Josh thinks about a girl that he once dated long-distance, whom he used to call on the cordless phone. It didn't work out between them.
Josh sees Emma come outside to go for a jog and he hides so she can't interrupt his possible phone call.
He thinks about how everything has already changed just because he knows his future. Case in point: If he hadn't found out he was going to marry Sydney, he would never have talked to her in the first place.