tl;dr normal ⇒ usual
normal ⇏ desirable

<rant> It is normal, same as it was normal for most people to die after being treated by a doctor in the pre-modern-medicine period.
Same as it is normal for people to start needing eye correcting glasses around 25y (quote from a qualified professional doctor).
Same as it is normal to be absolutely drained after just 8 hours of working on a desk, because it is also normal to have a closed-loop AC system with the only opening in the room (the main door) having people smoking tobacco on the other side. </rant>