If you want you may believe that the nirguNa brahman, in order to shower its grace on you, works for just that moment like saguNa, and then after sending you inside the core of your heart, within there it remains nirguNa and takes you over. Instead of resorting to such wishful thinking, the best thing would be to go forward with shraddhA and shraddhA alone!
Memory does go back to the Ishvara (saguNa brahman). As long as there is a mental action, thinking of anything good does bring back the memory of Ishvara, who is the aggregate of all that is good.
Except for advaita, all the other schools of thought earmark him as the destination.
How can an advaita-sAdhaka not think about Him?
But when that thought does occur, start thinking: “Oh Lord, it is because of your Mercy my mind has ventured into advaita. And by Your Grace I am moving on this path little by little. I know you are doing all this, in your great compassion, to take me over finally into your advaitic oneness. So if I now worship you as a saguNa deity, I will be going against your own sankalpa. Please help me go forward on this same path”
- This is a kind of expression of gratitude for the path so far trodden and a prayer for the path that is remaining, so that the mind still stays on the nirguNa principle.