I am definitely NOT one of those people.
I can drink a coffee at 9 pm and be asleep at 9.10 pm.
Coffee does not seem to affect me and I do not drink instant coffee but proper ground coffee made in a machine and into cappuccino or latte.
I always wonder about people who will not drink coffee in the afternoon, some 8 hours before they are actually going to bed -cannot relate to this.
My parents also always had their "supper" at 8.30 pm which included brewed coffee, and cake..