Another identification request
Hi. I have a large, fast-growing plant that has appeared in my border that I do not know whether is a weed or not. I have left it to grow so far as I know I planted something in that spot last year but I can't remember what! The reason I have now questioned whether it is a weed is because I've seen the same thing growing behind my house on the edge of a field. My neighbour says she removed one from her front garden a few years ago (not knowing whether it was a weed or not either) and said it has thousands of tiny needles/thorns growing up its stems, and gloves should be worn when taking it out. Any help appreciated. Pic (hopefully) below. Thanks.