An easy way to do this sort of selection is to click on the start of
the text you want to highlight then scroll to where you want to select
to then hold down the [Shift] key and click on the text - it will
select everything between the first click and second click.

As for Ubuntu mouse control, there are applications in Ubuntu Software
Center to help with this ( particularly on laptops ).

Now THAT'S the answer I was looking for. That's even better than the
way it is in that other OS.

To be fair, that trick works on *any* OS and has done so for many
years. It's just not widely known as the mouse prevails over the
keyboard for most users. Same as holding down the [CTRL] key whilst
selecting items with the mouse to 'cherry pick' an assortment of files
from a folder, or using [CTRL]+[C] for copy / [CTRL]+[V] for paste.
Often the combination of keyboard and mouse is faster and more elegant
than using either alone.

It works well in Kubuntu, but KDE is different from GNOME and is highly
configurable. However, it defaults to single click, which I prefer. GNOME is
more Windows like in this respect. It uses double click, but it lacks the
configurability of Windows or KDE. You might want to try out KDE and change
the mouse to double click. It will give you more control over the OS but
still stay with the Ubuntu family with same repos and applications. As an
added bonus it has one panel at the bottom by default, like that other OS.