Its the scans that you have to use with them and the cross referencing the information. Mainly in instrument flying
When you first start out you need to think dot to alt wings to DI where the dot is you pitch refence on the AH and wings is the roll reference for straight and level.
Each manover or phase of flight has its own scan depending whats the important information. After a bit you don't even realise you are doing it. And your eye will take in the required info and your hands and feet will sort it out and give you capacity to think at the same time as well.
The glass is just presented with little requirement to scan and if you do fixate on one instrument the others are within your field of vision.
Once you have the steam scan battered into you its a bit like riding a bike you might be a bit rusty but it soon comes back.