@Bana If you think any two people are basically the same person, it probably does say at least something about them, but more than anything it means that you just don't know them that well and are ignorant about their differences.
This isn't a philosophical or anthropic argument, it's just how reality works on a basic, logical level. It's statistically nigh-impossible for any two members of the species homo sapiens to be fully mentally alike, even if you stick to the low level of precision we call "for all intents and purposes".