I was previously logged into my machine as "olduser" , did some emails 
etc, logged out and logged into "currentuser".

I ran top and it shows 3 entries for the previous "olduser", i thought these
would have been closed down when i logged out of "olduser".

The entries are: 
olduser      8993     1  0 10:32 ?        00:00:00 /usr/lib/systemd/systemd
--user
olduser      8994  8993  0 10:32 ?        00:00:00 (sd-pam)
olduser      9766     1  0 10:34 ?        00:00:00 kdeinit4: kio_http_cache_ e

I have logged out of "currentuser", logged back into the "olduser", as i was
logged into "olduser", i did a "ps-eaf | grep -v root" and it did not have any
processes that didn;t belong to "olduser".
I logged out of "olduser" again and logged back into "currentuser" and these 3
processes for "olduser" are still running within "currentuser" session when i
do "ps-eaf | grep -v root"