Keep a diary. Human memory is unreliable and often fills in the gaps by the best guess -- if you believe something now, your memory will try to convince you that you have always believed it (unless you have dramatic evidence to the contrary), because it is easier than tracking your beliefs over time. (Also it protects you from the emotional pain of knowing that you have changed your mind.) A diary may show you that the past was not as you remember it.
At least this is how it works for me. I have no dramatic conversions in my past; my opinions have changed fluently. So absent hard evidence it is easy for me to imagine that a 13 years old me (the earliest I can remember having actual opinions on things) was basically just like me today, only in a younger body, minus all the experience and professional skills. But when I found my old diary, I screamed in horror and quickly destroyed the evidence.
The parts of my personality that stay mostly unchanged for a long time are values and preferences. As far as I remember, I was interested in math and later in computers, I was interested in truth and helping others. (I have some evidence for that, such as doing math olympiad, or getting in trouble because I asked too much.) My beliefs, however... let's just say that before 30 I was quite stupid. Yeah, I didn't feel that way. Most stupid people don't.
3Andrew Burns
Before 30, I was also a moron. But I only know this because I had an ideological epiphany after that and my belief system changed abruptly. Scales-fell-from-my-eyes type situation. When I turned 33, I started keeping a diary because I noticed I have a terrible memory for even fairly recent things, so maybe going forward subtle changes will become more salient.
That said, some things seem more impervious to change. For instance the "shape" of things that give you pleasure. Maybe you liked 3d puzzles as a child and now you like playing in Blender in your free time. Not the same thing, but the same shape.
I'd say what changed for me was my model of the world, other people, myself, and a corresponding change of priorities.
Being an (officially undiagnosed) asperger, I basically had no idea how other people think and behave. I did things that felt natural to me, and people reacted, often illogically. Didn't realize that most people lie most of the time, and even when I started suspecting that, I wasn't able to figure out the truth.
But it wasn't merely my personal stupidity. It also feels like I was culturally discouraged from figuring out the truth. Thinking n... (read more)