Your head weighs about 4.5 kg. That’s a considerable amount of weight to not support correctly.
You put a massive amount of pressure on your cervical spine when you’re looking down and if you do this continuously for years you will change the shape of your spine. Aside from making you look like a bit of a throwback to the Paleolithic era it can also lead to disc degeneration and nerve damage.
Fear not, forward head carriage can often be arrested or reversed. A good start is to ensure your ears are lined up with your shoulders. If your posture is correct, you should be able to drop a plumb line and your ears, shoulders, hips and knees should all line up.
Taking breaks during the day to simply look up and stretch your shoulders back can work wonders. This is a good starting point- your Neanderthal neck won’t be fixed overnight, but being constantly aware of your posture can really help.
A few sessions with a physio and some tailor-made exercises can work wonders.
Think about it- if you are continually cutting of the blood supply to the brain, you’ll always be foggy- just not enough oxygen can get delivered. As a consequence, you’ll often feel fatigued.
By giving your brain sufficient oxygen and other nutrients, you’ll feel better and sleep better. Not a bad result for doing something you Mum probably harped on. (Shoulders back and stand up straight).