Curate, connect, and discover
A lot of witches will tell new witches (baby witches) that they should start by learning and using protection magic. However, I've started to see a lot of witches say that protection magic is not as important as other witches claim it to be. Saying that they don't have anyone coming after them or an enemy in real life to warrant a spell of protection.
I think this may also be due to how I've not personally come across anyone really explaining why a witch may want to use protection magic all the time.
Now, it is true that there's no need to be paranoid all the time and have protection up 24/7. But here's a list where you may use it, find it useful, or haven't thought protection magic could be included.
An actual person -- This one is obvious, you have an enemy in real life or on the internet and you need protection magic to protect you from their curses.
A malevolant spirit -- They can come from your windows, mirrors (including tv screens, computer screens, and other reflective surfaces maybe), they seep through floor cracks, hanging onto your coats from outside, etc. Just like how you'd use garden gloves to avoid dirt up your nails being trapped there. Protection magic is just like putting on those gloves.
An energy -- Say you have a neighbour who's arguing with someone. They're yelling and screaming and it can be heard through the apartment walls. That negative energy is seeping into your home and your energy. So it may be worth protecting your home and energy from that sour neighbour's energy. (ever been scolded by your mother and your mood is sour? it's kind of like the same here.)
Your own spell -- Now a self-love spell is probably not something you should protect yourself from. But let's say you're doing a curse. It would be a smart idea to make sure you're protected before beginning such a spell. Much like how you'd wear an apron to protect your clothes from stains when cooking food. You may not always spill your food when cooking, but damn it is it annoying when you do and the stain won't wash off. It's the same with a spell.
Unintentionally -- Sometimes things can happen that's out of our control and it's a good idea to be a little prepared. A black cat suddenly running across the street? Bad luck. Someone got jealous when you told them something good? Evil Eye. Think of it as going to the store with an extra bag for your groceries. You may not need it, but isn't it handy when you at one point do need it?
Protection magic doesn't have to be elaborate or grand or be convoluted. Protection magic is powerful but also extremely simple. All you need is a horseshoe above the door, a little talisman in your pocket, a sigil for your car, etc.
So don't dismiss the importance of protection magic. It may help to improve your spellwork and your energy.