Insensitivity - Is it natural?

Last week, I was informed over the phone that my grand mom passed away. For 2 hours or so, I was distraught. I started reminiscing about old school vacation days when we would go to Kallepuly, Pallakad where our grand parents used to stay. Memories like how I used to dislike my grandpa as he used to make us write maths tables on vacations, make us sleep early and beat us whenever we were indisciplined, how I used to like the calming effect of my grandmom, how I used to touch her very smooth stomach with my palm and say "Aiyee, so smooth", How we used to play in the lawn, and then the last time I met her. It was 2 years back and she had grown really week and frail. I felt guilty as I had spoken to her just a week back when she enquired when I will come to visit her (now that she was in my folks house) and 2 days back where she expressed her happiness over my change in shift timings.

But then, after those 2 hours or so, I did not feel much. Of course, there is a certain tinge of something missing but not exactly the kind of grievance you would attach to this kind of tragedy. I know I am not exactly spiritually evolved as I remember getting up one morning very sad as I had a very bad dream where I witness my brother in an accident and then go running around scared(I still remember that pain I felt at that time, It was so real). So is it that her being old (she was in her 80's) made me not feel a deeper grief? Or was it the emotional distance I had acquired due to not meeting here regularly or talking to her frequently? I feel it is a mix of both. But this insensitivity... It makes me wonder, why?

Not sure what answers I am looking for while I am writing here... But just thought of penning this down, a sort of confession. I feel a certain amount of guilt for this sort of indifference or insensitivity I have (whichever it is).

Not a means to justify it, but I have deep belief in nothing reallly dies but "passes on" to another form/stage/life. I hope and wish that the currently departed soul flows through the cycle of life and experiences all that it chooses to and gets nearer to the oneness we all seek...