Right, and what you recommend in those situations where, due to unusual circumstances (flat battery, whatever), you need to access to, say, your online banking

Right, and what you recommend in those situations where, due to unusual circumstances (flat battery, whatever), you need to access to, say, your online banking or airline site or email or whatever using another device that would have no way of knowing who you are? If there's a way to access a web-based password manager securely from any device, then surely there's a way to access whatever application you actually need access to securely too... FWIW I use a password manager of sorts, but only to remember "hints". Once I see the hint I can reliably recall what the full password is, but there's no way reasonable way for someone else to do so. It's only passwords I use very rarely I even really need such hints for.