Your bedrooms needs to be a calming space - doing work, checking emails and scrolling on Instagram heightens brainwave activity, making you feel like you can’t ‘switch off’. Conversely, by limiting these type of behaviours, your brain understands that bedroom = relaxation, and you get to sleep easier, and are less likely to wake through the night.
Think of what happens when you see a toilet - your brain automatically thinks ‘do I need to use the bathroom?’ This is the exact thought process you want for your bedroom, except that you want your brain to understand ‘ok, it’s time to relax now’, simply just by seeing your bed.
For fellow science buffs, this reflects the psychological methodology of classical conditioning (yes, like Pavlov’s dogs!), and this specifically is re-conditioning.