Yes, if someone opens up to you about personal stuff that they wouldn't share with other people, it can be a sign of a possible friendship or a deepening bond. When individuals feel comfortable and safe enough to share their personal thoughts, feelings, and experiences with someone, it indicates a level of trust and emotional closeness.
Sharing personal information requires vulnerability, and when someone chooses to be vulnerable with you, it often means they value your judgment, support, and understanding. It shows that they see you as a trustworthy and non-judgmental person with whom they can confide.
Of course, friendship is a complex and multi-dimensional relationship that develops over time through shared experiences, mutual understanding, and genuine care for each other. Opening up about personal matters is just one indicator of a potential friendship, and it's essential to continue nurturing the relationship, being supportive, and reciprocating trust to strengthen the bond further.