do i really need a thermostat most men tell me they are useless

The thermostat keeps a fully warmed vehicle at a constant engine temperature so that your heater works properly. An engine that runs at too cold a temperature can also use more fuel, as the vehicles computer will keep things at a rich mixture, something like having the choke partly closed on a carbureted engine. So, yes, and in most cases a thermostat replacement is simple and cheap.