I mean the "hey's" had like 9 months to a year between them being sent, it was hardly harassment, probs just a case of the person popping back into their head again so they thing I'll try sending a message again and see if they respond, its been a year since I last tried to talk to them. Who ever the ghoster is just had to say "please stop messaging me and delete my number" after the second one if it was bothering them. But usually ghosters ghost people as they know it leaves them emotionally traumatised and still attached and then they can just jump back in where they left off even years down the line sometimes as the person was left with no closure.