Agreed but he doesn't have the commitment to banging on the same drum for a couple on months, he'll never cope with 20 years.Also, if he takes his dad as an example, he likely figures that all he has to do is keep trying. After all PC was laughed at back in the day with his talking to plants routine.
So harry would like to be as empathetic as his mum and as forward leading as his dad.
Therefore if he keeps banging the drum about the same thing in approximately 20 years he figures he will be listened to.