The Strange abd Mysterious World of Win10 Updates

Several times a year, my computer response time plummets like a wounded
robin, and usually at the same time, I can't seem to start some of my
applications. Either nothing happens at all or else I get a few seconds of
the hourglass followed by nothing at all happening. I finally noticed,
after this happened several times, if I click on the 'Start' icon and then
on the power icon, I see the little orange dot and the message 'Update and
restart' or 'Update and shut down', depending. When I click on one of them
(usually 'Restart'), the machine goes through its usual couple of centuries
of 'Do not turn off your computer' and finally completes the update and the
restart. And surprise, surprise, when that's all done, my computer is
running at its normal fast speed and all my applications start normally.
So does this happen to any of you, and if it does, do you have any idea of
why the system behaves the way it does when updates are pending? Or is
this just another example of Microsoft being Microsoft?