The reason it blinks after letting it sit is because all the oil runs back down into the pan when you turn the car off, and that takes a while. Your oil pump must fill your engine all the way up to the squirters before you'll actually see that oil pressure light turn off... because the squirters act as resistors to build up oil pressure.

You don't want your engine running when that light is on. That's all I was meaning to say in this. When that light is on, the squirters aren't squirting. When there's no oil in on your bearing surface, you get metal-metal contact. That's when wear happens. Properly lubricated parts don't wear.

Roll with it. When it starts knocking loudly at startup, take it in for service. If that light starts coming on in any other condition, take it in for service.