Martin Gregorie  wrote:
> On Tue, 11 Dec 2018 22:27:51 +0000, A. Dumas wrote:
>> Yes. However, effectively, Raspbian is a root-only OS because the
>> standard user Pi doesn't need a password for sudo.
>>
> What version are you running?
>
> How recently updated?
>
> Mine, which has been running Stretch for some time, is always fully up to
> date as of 'last Friday' because that is my offline backup + update day
> for all my systems, Sudo always prompts for a password if it hasn't been
> used for the last 5-3 minutes.
>
> Admittedly, while ago sudo stopped prompting for passwords. That might
> have been when I upgraded to Stretch - I forget exactly when, but a month
> or three later sudo got updated and since then has asked for a password
> as you'd expect it to.

Has always been the case from the very start of Raspberry Pi (Raspbian)
until the latest versions. If it's different for you, you either changed it
for user pi (and forgot about it?) or you are logged in as a different
user.

--- SoupGate-Win32 v1.05