tl;dr: I just mapped Y to "+y and I am very pleased with it.

A coworker saw me copying some text out of Vim and humored me: everything seemed to happen like magic in my editor, but for a simple thing as copy and paste I needed a lot of keys.

It is true: in order to copy text within Vim, you can use the y command, combined with the motion of what you want to yank. So: yiw will yank inside a word, ggyG will go to the top of the file and then yank until the bottom (so, the whole file), yy will yank a full line. But these yanks are only pastable (with p) within Vim itself.

In order to get text out of Vim, you need to use a special register. Registers are a sort of named boxes, letters a to z, in which you can put snippets of text. To use it, you prefix your yank (or delete) with a quote: "ayi( will select register a and then yank the text within parentheses. To get to your system clipboard (the one all other programs use), you select the special register with "+.

Thus: my coworker saw me hunting for the "+y combination, probably. I almost always look at my keyboard when I do that, so awkward is the combination. But I just found a solution: Y.

nmap Y "+y
vmap Y "+y

By default, Y does a yy, which I never use, because it's inconsistent with other commands. D, for example is equivalent to d$, delete until the end of the line, same for C as c$. I guess it makes Y play along with V (line-wise visual select) and S (subsitute full line), but I always use yy anyway, so Y is free to use. When I now want to yank to my system clipboard, I just use Y instead of y and that's it.

You can also consider adding this as gy, which does not have a meaning, but g combines with various commands to activate variation of their meaning, so it's not a bad choice either. I mapped it to both and will see which one sticks.