SPICE simulations with LTSPICE showed no current flows thru drain & source of an enhancement n-channel MOSFET with using its SPICE model - yet hooking up 5v 2A power supply across an actual device (IRLB3034PBF) yields full current flow with nothing hooked up to the gate, another words no voltage into the gate, it was entirely not attached. Is SPICE incorrect about current flow?
A MOSFET's gate is floating and well-insulated thanks to the oxide layer between the gate and channel. As a result, when it is completely disconnected, Vgs may very well be anything depending on handling and other effects. You could have very well deposited enough charge on the gate for the transistor to turn on, merely while handling it. It is almost never correct for the gate of your MOSFETs to be truly floating unless you are doing something highly specialized, such as producing flash memory. You should find that, when the gate is driven in a sensible manner, then SPICE and experimentation will roughly agree.
SPICE just sees the small capacitance and leaves the gate potential at its initial conditions unless influenced to do otherwise.