"It's not your fault" or "What you see isn't what they get"
One of the things I tell customers a lot is what I call "The lowest common denominator" rule.
For a lot of people their computer is a single machine.
But, much like your car, the computer is made up of a variety of parts that work together to do a job. The quality of those parts and how they work together determines the overall performance of the computer.
If you buy a cheap computer, in the same way you buy a cheap car, then you can expect it to be slow.
If you buy a car that is flashy and expensive on the outside, but you skimp on the engine, then guess what? It is still going to be slow.
If you buy a proper fast car without any compromise, but you only drive it on dirt roads, then guess what? You are still going to be slow.
In that last example you can correlate the road to your internet connection.
So let's imagine you get it all right - a fast car and a fast internet connection. All your ducks are in a row and they are all flying.
The next thing to hold you back is other people on the road.
There's the person doing 70 in a 100 zone AND in the overtaking lane, there's the city traffic that is at a standstill for no obvious reason, there's the highway moving slow because it is a long weekend and everyone wants to be on it at the same time...and so on.
All these traffic analogies relate strongly to the way the internet works and how things outside of your control affect you experience no matter how nice your "car" is.
There's a lot, if not almost everything really, about technology and computing that is like this.
You do the best you can but the experience is lacking at the destination due to factors outside your control.
A few examples that pop immediately to mind include:
1) Web sites - you build it and make it perfect but you have no control over what device will be viewing the web site and what size screen it has. Even if you could cater for every screen size known today, tomorrow some phone company brings out a folding screen or some other new screen size that thwarts your efforts.
2) Documents - you create a beautiful document but the people you send it to don't have the same word processor, PDF viewer, fonts loaded or maybe even operating system. So when they view the document it looks quite different to what you intended.
3) Colours - you go to quite some effort to pick the right corporate colours and branding, but because every screen is different and most people don't calibrate them, what looks like a lovely red to you is seen as a hideous pink to others. The same goes for printing.
4) Video streaming and other forms of web meeting - you are uploading one video stream but you have no control of how many people are watching and over what technology...screen size, internet speed, etc.
5) Downloading - your ability to get things from the internet is limited by the providers ability to send them to you fast enough. An example I repeatedly bump up against is how slow downloading Microsoft Office is in Australia. It always takes way longer than the internet connection or the target PC would dictate.
...and so on.
So it is not without significant personal pain and experience that I recommend you to do your best, but just "let it go".
I have seen many people spend way to long trying to obtain perfection at their end only to be let down once the thing is "in the wild".
I also see a lot of people quick to blame themselves and their set up for something that is outside of their control.
Being able to detect the lowest common denominator in any scenario will empower you to fix it or live with it (as opposed to chasing your tail and never getting anywhere).
Understanding this cascade of dependencies and limitations will help you troubleshoot problems and know how to spend the right amount of effort to get things "good enough", because perfection is way outside of our control.