I have no idea how to knit, do you knit?
I do a bit.  It can be done by hand or by using a machine.  I can only hand knit.
I've seen people doing what they call arm knitting with really big yarn
Yes I saw that! Never tried it though. Its only a new thing, I think it gained popularity during 2013/14.
It looks really neat - but i have no idea where to buy yarn that big.  My grandmother tried to teach me to knit once, but it did not go well
lol it definitely takes practice.   There are so many needle sizes, stitch types, fibre types to figure out and with me the finished product always ends up too big no matter how well I follow the pattern.
I love the blankets that she made for us before she passed - they are very warm and pretty
and they last for years I bet.  
Yes, i've got one i've had since I was born 45 years ago and a few even older than that
isnt it lovely to have things like that, with such memories. Maybe you should try knitting again, just pick your needles, wool and loop it on and get going.  It is just a row of loops stiched together after all.