Over my many, many years in computing I've had to deal with many and varied power related issues.
From shocking myself on my home built kit computer (I got thrown across the room more than once) to the mainframe on diesel generator back-up power that went up and down like a yo-yo (I'm sure I've told you that story somewhere).
The question I get asked the most is "should I leave my computer on or turn it off?"
The answer has never been straightforward and probably still is confusing today.
So I won't bore you with the history lesson, I'll just let you know where I think we are today.
Firstly, laptops and other battery powered devices.
OMG!!! There are so many types of batteries and devices that providing you with some useful generic advice seems nearly impossible...but it isn't...I don't think.
For your battery powered devices you should:
Run them on battery until they are flat once a week.
NOT run them on mains power all the time (UNLESS the battery in them is already stuffed).
Be prepared to replace the battery at some point - it could be 2 years ish or more.
READ the battery management information that came with the device - because it WILL vary from device to device.
Secondly, for mains powered computers - desktops and the like, the choice is fairly simple:
Power down your computer at the end of the day.
Turn it back on in the morning i.e. when you start work or need it first.
There aren't many personal, or even small business, reasons why you'd leave a computer running 24x7 these days.
Even if you do try to leave your computer running 24x7, unless you are onto all the power settings it has, you may find it goes to sleep on its own anyway.
Most computers do still benefit from a full power down so it doesn't hurt to make that part of your daily routine and save some power into the bargain.
Thirdly, other computers you may not even know you have.
These days a lot of things are called "smart". Obviously the term is fairly loose, especially in the context of some of our "leaders", but what it means for you is that your "smart" devices contain some form of computer and they too could and will benefit from the occasionally power down.
For example, your smart TV is quite probably just a very big smart phone and running an operating systems that requires all the updates and patches that mot other computers need these days.
These smart devices will run "apps" from third parties and, no matter how reputable your device manufacturer is, the third parties can and will cause you problems...and, so will the manufacturer from time to time.
Another common contender for a power down is your Internet modem and/or router.
From the outside these things look pretty non-functional - just some flashing lights and hey presto, internets!!!
But they too are little computers of varying power. Whenever you experience a slowing of your internet or an outright failure, check your modem/router and give it a power down.
You may be surprised how often this helps.
If in any doubt, and with electricity prices being what they are these days, I suggest you power down devices when you aren't using them.
A lot of them even use power when on standby and every little bit of standby-power adds up on your electricity bill.