This may be of interest to you unless of course you don't mind your computer frequently going on the blink.
If you keep your computer constantly powered on and at a constant temperature, you should get a very long life out of it.
Some electronic devices are easily killed by power surges or brownouts. Most modems / routers are safe as they run through a step down transformer. A lot of these are designed with a small chip that keeps the output reasonably constant though significant spikes will kill them.
The other thing that kills electronic equipment is temperature fluctuations. Electronic components will expand with heat. Keeping your device on and in an area where the temperature doesn't change too much is one of the best things you can do. The expansion and contraction repeated over and over will slowly cause the components to develop faulty connections, become intermittent, or maybe not work at all.
This can be seen with computers that are turned on during the day and off at night. They typically will die or have intermittent faults a lot earlier than their counterparts which are left on all the time.
It's never too late to start doing the right thing. The final decision of course remains with you.
May you enjoy many happy and faultless years with your computer and other electronic devices.
I am sorry that I have to be "awkward" once again!
I am aware of what you are saying. I have heard it before. Although, there is two sides of every matter...
I read this on a site (I can't confirm that it is true of course as everything you read on the net is not true, is it):
"One computer left on 24 hours a day will cost you $115 - 160 in electricity costs a year and dump 1,500 pounds of CO2 into the atmosphere. A tree absorbs between 3-15 lbs of CO2 each year. That means that 100-500 trees would be needed to offset the yearly emissions of one computer left on all the time."