I often hear people say they have seen that the self / ego is an illusion and that they are “the one” – but then they lost it. They often say things like “the ego came back” or “life got in the way”.

I’m hear to tell you that the realisation that can be lost is not a real realisation.
Realisation is a binary event – you either have it or you don’t. There’s no middle ground. There’s no partial realisation. It’s black and white. If you think you’ve had it and then lost it – you never had it in the first place.
It’s okay – that’s just sometimes part of the journey, a step in the process. But if you’re fooling yourself by thinking that you “had it” and then “lost it”, then you’re not going to make much progress.
Realisation (aka awakening aka enlightenment) is the direct recognition that the idea that you were somehow separate from the rest of the universe (aka “the one”) was an illusion. It’s the single most profound experience there is. It’s the end point of every spiritual journey. There’s nothing to do afterwards. It’s waking up from the dream of the self. This is not something that you can “forget” or “lose”. It’s the total annihilation of the idea you’ve had you’re entire life of who and what you are. This isn’t like putting your iPhone down somewhere absent-mindedly after a night on the booze and then not being able to remember the next morning where you left it. This is more like being told by your doctor that you have stage 4 cancer and only a month to live – no matter what happens next, you aren’t going to forget.
The other misnomer we should talk about is the idea that realisation is a slow process. That’s bullshit. It happens suddenly. That’s because there is no middle point between “I’m separate” and “I’m the entire universe”. Again – it’s binary. There are only two positions for the light switch – on and off. There’s no half on, like there’s no being half pregnant.
Sure – you might take years or even decades to get to a point where you have the realisation. That’s not debatable. But that’s doesn’t mean the process of realisation is slow. It just means you weren’t ready to let go of your illusions for a long time.
And once the realisation has happened, there is no putting the cat back into the bag. No matter what happens next – no matter what kind of shit life throw at you, it doesn’t matter, because you know – YOU KNOW – that it’s all an illusion. There isn’t – THERE CANNOT BE – the slightest confusion about it.
Sometimes people try to suggest that post-realisation, old habits still crop up and that somehow can make you forget that the self is an illusion. That’s bulshit. It’s true that the mind will continue to throw thoughts up post-realisation. But those thoughts, if they pertain to the idea of a separate self, have nowhere to land, so they immediately evaporate.
Any thought that appears that hints at anything to do with a separate entity, an “I” (as in “I’m not worthy”) or a “they” (as in “how could they do that to me?”) or a judgment (as in “I wish things were different”) cannot exist beyond the moment because once we have realisaed that the self is a total fabrication, the ideas of “I”, “they” and judgment completely cease to exist. They cannot possibly exist post realisation. So while thoughts like “I’m not worthy” might pop up, they have nowhere to land – they cease to make sense and, therefore, cease to be a problem.
People also sometimes say “it feels like we have free will”.
No. No it doesn’t. Here’s why.
Your brain doesn’t come pre-pacakged with models for interpreting data. When you’re born, you don’t come out of your mother with fully constructed ideas of how the world works. You don’t know shit about free will. You can’t – the parts of your brain that handle abstract concepts and language don’t finish growing until you’re about two years old.
And yet, during those first two years, your senses and your brain are still taking in sensory data. You just can’t do much with it beyond simple reactions.
Eventually, as you get older, someone explains the rudimentary concept of free will to you – that you are somehow responsible for your actions – and you believe them. From that moment on, you interpret data using the model of “I have free will”. It doesn’t *feel* like you have free will – that’s just the model you use to interpret sensory data.
If you have the model “I don’t have free will”, then your brain will take in the exact same sensory data as before, but you’ll interpret it differently. It doesn’t feel any different – you just have a different model for making sense of the experience.
It’s like that story in Stephen Covey’s book “The Seven Habits Of Highly Successful People” where he’s sitting on a train and there’s a father sitting across from him who has two young sons who are making a lot of noise and annoying other passengers while the father just sits there blankly. Covey finally has enough and asks the father to do something about his children, thinking he must be the worst parent around. The father snaps to attention, apologises, and explains that they are coming home from the children’s mother’s funeral. She died suddenly in a car accident a few days prior.
All of a sudden, Covey’s model for interpreting the data of the father and the noisy children is turned upside down. He doesn’t see him as a useless father and rude citizen, but as someone lost in grief whose children are obviously also grieving and don’t know how to process the untimely death of their mother. (I’ve probably got some of the details of the original story wrong, I read it 20 years ago, but you get the idea.)
When our models about how and what we are fundamentall change, we’ll never look at ourselves – or the people around us – in the same away again.
Until that realisation occurs, however, you may have glimpses or little insights – but don’t mistake that for the actual realisation. Stick to it. Persist. Find out if the self / ego exists. Don’t give in until it’s all gone – permanently. This is the only way to freedom.