Not a dumb question G&T.
Pitot and static tubes rely on ambient air to gather info to present to the airspeed indicator, altimeter and vertical speed indicator. Blocked pitots (either through human error or Nature) are a fact of life.
Pitots and static air pressure sources (which old school drivers like myself call "weatherheads") in something as unwieldly complicated as a bloody 320 are sent to computers that poke their fingers into places you wouldn't even begin to fathom - thus if these computers get the wrong data all sorts of bells and whistles go off for subsystems that are actually working perfectly. And yes its intially bloody confusing when it happens. That's why some of us do our preflight walkarounds checking the weatherheads as a separate inspection from the rest of the aircraft, esp when its been in the hangar for maintenance or first flight of the day.
However, risks are always there for blocked pitots (I had one struck by lightning once) but we're trained to deal with it.