Rosemary does not NEED to be pruned. They respond well to regular pruning, but don't need it. I give mine a whack every year just to keep them orderly.

I only trim mine because it takes up a lot of space in my tiny garden. A little haircut from time to time does encourage new growth, especially in the middle of the plant, but if the tree looks healthy, and you've got the space, and don't mind plants looking au naturel, leave it be.

Yes, your friend really DOES know everything, just ask her! But your rosemary is just fine without pruning. I like to nip and snip to use rosemary in cooking, and the big branches stripped of their leaves make great shish kebab skewers. But other than that, my rosemary does what it wants to do!

Nothing NEEDS pruning - how do you think plants survive outside our gardens? But rosemary can get quite large and it can get sprawling. I just cut mine back when it blocks the path. Whether you prune yours or not is up to you. As Daisyd says, it's entirely down to your preferred gardening style. Personally I have to say that lots of the gardens shown on GW look too controlled to me. Some people seem terrified of their plants and like to beat them into submission with rigorous chopping and a no man's land of bare mulch (probably mined) around every plant.

I hope you are using-pruning it all the time, else why have one? I bury the long ends and then find homes for the new shoots. They do sometimes die from the inside out so I like to have extras just in case of a lose of the parent plant, plus I enjoy finding new homes for this herb so more can learn how to enjoy using it in their cooking and not just for looks.