it depends a little on humidity. static tends to build up more
when the air is low humidity.
it's good to discharge yourself to ground or a large conductive
object before touching your computer. e.g. an unfinished
surface on a metal desk, careful of sharp edges. or a screw
in the power supply case (which will usually be close to
electrical ground.)
the legs on my desk are metal so i just touch those before
touching the computer.