With banks and financial services in general being a bitch about changing contact details. That's a form and a visit to the branch for each bank, broker, investment advisor, direct fund provider. That's already almost 30 applications. I haven't even counted stuff like vehicular services, government tax portal, property tax portal, electricity provider, gas provider, internet provider. Not all of whom allow changing for email address digitally or without some complicated support ticket.
It's such a mountain of changes I myself have only gotten through the list halfway and it's been 4 years of trying. I can never recommend that to anyone in my family, they'll just hate me.
P.s. This might just be my country specific problem, I understand other countries are easier.