Much of our everyday remembering consists of information coming to mind involuntarily. ~ Georgian psychologist Lia Kvavilashvili
An involuntary memory is a spontaneous recollection without conscious effort. Distinct brain pathways are activated during involuntary memory from that of conscious recall, as nattermind works a different groove. The character and conditions under which involuntary memories occur vary greatly.
The problem with our memories is not that nothing comes to mind – but that irrelevant stuff comes to mind. ~ American psychologist Benjamin Levy
Insight related to the incubation of solving a problem, recovery from a tip-of-the-tongue state, or sudden remembrance of needing to do something (prospective recall) are exemplary involuntary memories; all of which proceed from conscious thought with intention.
Involuntary memories also arise without previous provocation. They may be most unwelcome. Intrusive memories may keep coming to mind despite attempts to suppress them. A flashback of a traumatic event is exemplary; such is the bane of victims of post-traumatic stress.