I think the age that a person deconverts is most likely to coincide with finding some challenge with religion. For most people who lived in the 1800's, religion wouldn't have been challenging at all. For those who live in, and fit into a religious community, there is no need to question it, no challenge at all.
In our contemporary world, if you gravitate towards a lot of scientific materials (documentaries, periodicals, etc) then religion fast becomes a challenge. You could be drawn towards art or music, however, and encounter far less of a challenge while still being very intelligent.
I grew up in a home where you were never aloud to question, but do as you were told. I saw my mother going from one religion to the next and we had to follow and do as we were told even ended up in Santmat. Religion was switched between bouts of drinking for my mom and her being bipolar searching for some form of crutch. I believed because that was the only thing that made sens as a child , that maybe this Jesus they spoke of would oneday come and change my misserable childhood. I remember the fear when I read that I would pay for the sins of my fathers, that was just horrible as a girl age 13 for the first time I questioned, because Jesus was suposed to have deid for my sins, and my parents, parents must have sined like hell for me to grow up in an abusive home. I still clone to hope until age 29 when my husband was murderd and religios people came to show simpath and said things like "It is Gods will" " he is in a better place" God decides when it is our time" " He deid at the hands of Satan" "God pics his most special flowers" Now that got me thinking. If this God is so loving why would he think that a one year old girl and 5 year old boy needs to grow up without a father. Was it God or Satan, just did not make sense anymore. I decided at age 38 to finish school and started to study psychology, some om my subjects were socio cultural anthropology and philosophy that and The God delusion opend my mind, only then did I start educating myself. So for me it realy did start on education, but my childhood did not leave room for me to start this prosess before an later age, nothing wrong with my IQ I was conditioned not to think for myself, not to question and blindly follow. I will never force my opinion on to my children but will leave them room to grow and find the truth, to read, read ,read and yes question even adults because adults is not always right.
Hmmm...actually I was born an atheist. I didn't believe in any deities at that time. My parents sent me to Sunday School but I think that was just to get me and my brother out of the house on a Sunday morning.
Anyhow the teaching didn't stick, I didn't believe the fantastical stories were any more true than the other fantastical stories I read when I was a child and I don't think I got the idea that they were supposed to be true as they were obviously impossible.
As I got a little older and realised that the adults thought the stories were true (kind of, to suit their own purposes...what's that about?) I thought they were a silly. When I raised the the issue I was asked to leave Sunday School as I was a disruptive influence! And not much has changed since...
I had been moving farther away from religion as time went by. I was raised Catholic, and so much of the doctrine disagreed with what I felt was right as a person. It was a very gradual thing for me, and I guess I didn't even really think of myself as an atheist until one of my friends called me one. Then I was like "Yeah I guess I am" I really started to look at things a lot more critically and here I am. I may have lost a few friends, but noone I was really close to. Most of my Christian friends just agree to disagree with me. We debate from time to time, but nothing too bad. My girlfriend is a Christian, and knew I was atheist when we started seeing each other. We respect each others views, but don't really talk about it...
I was raised in an atheist household but it wasn't until my early 40's that I had the epiphany that caused me to stop feeling like I had to be open-minded about religion. I investigated, I prayed, I tried to believe but I just don't. I not longer apologize for it or lie to keep the peace. I try to be tactful about it, but I am who I am and it is up to others to accept it or not.
Yours is an odd, very out-dated idea seen from the UK.
There's not really any more cloying overpowering religious community any more and hasn't really been for 50+ years. Most people are atheist or agnostic. Out in the villages it is still a bit weird and some institutions; cub scouts, House of Lords are still in thrall to the CofE but mostly religion is inconsequential in day-to-day life.
As an atheist, observing different religious communities over the globe it is lear that people are indoctrinated to the local religion by their parents initially and then the local community and religious community their parents bring them into.
OK - a lengthy lead in just to point out that your post should more correctly read; " When YOU became atheist again..."
Of course, nothing really changes. The sun still comes up, you still have to go to work.
With regard to losing people,the old one about losing a lover comes to mind. If they were yours they come back, if they don't come back, they were never yours. That is, if someone only liked you because you shared their views on religion then they never were a friend of yours. They are/were a weak person too, if they couldn't cope with their ideas being challenged.
So, the long and short is that you don't really change and what you lose can be borne easily as it's no real loss, and the upside is that you get to think for yourself and make up your own mind on topics. you have the ability to be better than any outdated religion...
You can make up your own mind on topics like contracepton, abortion, social care, god/bad, the law and sentencing, etc....a bit better than just being a sheep.