You cannot step outside your own head to check. The one running the comparison is the one who changed, working from a memory that got quietly rewritten along the way.
Paste something you wrote a while ago, and something you wrote lately. It names what actually changed and what held underneath. Free, no signup.
Nothing you paste is stored, and no account is created.
Two samples show you one gap, once. A reading starts a record with a date on it, so the next ten years are checkable instead of remembered.
Now the honest answer, which is that you are the worst available witness to your own change, and there is research on exactly how bad.
In 2013, Jordi Quoidbach, Daniel Gilbert and Timothy Wilson published a study in Science that ran about nineteen thousand adults, ages eighteen to sixty-eight, through a simple pair of questions. How much have you changed in the last decade? How much do you expect to change in the next one?
At every single age, people reported a great deal of past change and predicted very little future change. The thirty year olds described the previous ten years as transformative and the next ten as more of the same. Then the forty year olds, looking back at that exact decade, reported it as transformative. Everyone was right about the past and wrong about the future, at every age tested.
The authors called it the end of history illusion: whatever age you are, you tend to believe you have just now finished becoming yourself. Which means the feeling of "I am basically who I am going to be" is not evidence about you. It is a standard error, and you have already made it at least once.
People, at every age, believe the person they are right now is the person they will be for good. They are reliably wrong, and reliably surprised.
The comparison you are trying to run needs two clean readings: an accurate picture of who you are now, and an accurate picture of who you were then. You only have live access to the first one.
The second is a memory, and a memory of a past self is not a file you retrieve. It is a reconstruction your current self performs on demand, using current beliefs as the raw material. If you feel transformed today, you will remember your old self as further away than they actually were, because that makes the story cohere. If you feel stuck today, you will flatten a decade of genuine movement into "nothing has really happened", for the same reason.
So the ruler is made of the same stuff as the thing it is measuring, and it bends in the same direction. This is the honest reason the question is hard, and it is not a personal failing. It is a structural one. It is also why every quiz that asks you how much you have grown is really just asking how much you currently feel like saying, which is the ceiling on any self-report instrument no matter how well it is built.
The signs worth trusting are the ones that live outside your head, where your current mood cannot edit them.
And the signals that lie
There is a measurable answer and a philosophical one, and they disagree in an interesting way.
Measurable: yes, personality moves with age, and it moves in a direction. Across large longitudinal studies, most adults become somewhat more conscientious, more agreeable and more emotionally steady as they get older, with the fastest movement running through the twenties and thirties (Roberts and Mroczek summarised this pattern in 2008). But relative standing is much stickier. If you were more anxious than most of your friends at twenty, you are probably still more anxious than most of them at thirty, even though all of you are less anxious than you were. So two things are true at once. You changed. Your position in the crowd changed less.
Popular version, and it is wrong: this question usually arrives attached to the claim that every cell in your body is replaced every seven years, so you are literally a new person. That is not accurate. Turnover rates differ enormously by tissue, and most of the neurons in your cerebral cortex are the ones you started with. You are not a fresh build. You are a continuous one, which is the better answer anyway.
Philosophical: what makes you the same person across ten years was never sameness. It is continuity, the unbroken thread from then to now, with every change strung along it. A river that has swapped all its water is still the river. This matters practically, because it means "have I changed" and "am I still me" are not opposites and you do not have to choose. You can be substantially different and completely continuous. That is what a normal decade looks like.
If the feeling behind your question is not about years at all but about rooms, that you are one person at work and someone else at your parents' table, that is a separate question with a separate answer: why you act like a different person around different people.
Given all of the above, only three moves reliably beat the illusion.
If you want to do the first one properly and you are short on artifacts, prompts that get past your own editor will produce one worth keeping. And if the honest answer to "have I changed" is that you are not sure there is anything stable there to change, that is a different and more urgent question, handled in I don't know who I am.
Every personality test has the same defect, and it is not the questions. It is the date. A test scores whoever filled it out on one particular afternoon and hands back a type that does not move. Come back two years later and it either gives you the same answer, in which case it learned nothing from your two years, or a different one, and it cannot tell you whether that is you changing or just the instrument being noisy. Either way it cannot answer the question on this page, because it never held a fixed point to measure against.
A living record is the other shape entirely. LUX starts with six questions and about eight minutes, and gives you one word and a card dated that day. After that the word is not really the point. The date is. The back of the card carries what accrues: beats on record, which counts everything you have added; weeks active; and the day your record opened, which can only ever get older. When enough has gathered, the record compresses it into something shorter and truer, and then it grows again. The older reading is not deleted when that happens. It stays on the record as evidence of who you were, which is exactly the artifact you are currently wishing you had from ten years ago.
That is the whole argument, and it is an argument about time rather than insight. A test freezes you on the day you took it. A record moves when you do, and nobody can catch up to a record that started before theirs. The full walkthrough shows what the record holds and how it breathes. The word and the first reading are free, and the room around it is on the pricing page.