My bos told me that you can't create a loop with glass fibre cables is that true? Why is it different from copper?

I've got a few stickers
It's the first time a decorated my laptops :)

How is it possible to Hotplug RAM?

Everybody loves Python, but every documentation about a library is ***** (not good) or I am to dumb to understand? ( for example Pillow Tkinter)

Im new in my job now Im working for a half year and my boss is frequently saying to me that Iam stupid and useless.
I don't know but is this kind of normal?

I am actually programming in C# and i learned programming with this language, but my problem is that visual c# have mandy dependencies and i need a language which run on a windows 7 as on a windows 10 machine but with no dependencies to any DotNet-Framework oder any special DLL's is there a language for this?

I started programming with Threads (in C#) I though it can't be this difficult after i get it how to create a delegate right (2 hrs) and interact with my form without a crash (after another hr, but it didn't do this what it supposed to do) there popped up errors kind of randomly out of nothing and I have no idea how to avoid or catch them😩

Last week I made my own Website, I was so proud on it.
Today I told a friend absolut it and he shows me how to do it right with CSS-Grids.
Now I am asking me how coud I be proud on my old website