What does it mean that my boyfriend left one of my hairs on his body?

Different cultural backgrounds and belief systems may have different interpretations. Here are some possible explanations:

1. In some cultures, keeping one's lover's hair is considered as a symbol of love. This may be because hair is regarded as an extension of an individual and can represent a part of the body, or it may be because hair is considered to have some mysterious power and can maintain the feelings of two people.

In some cultures, hair may be regarded as a protector or a mascot. Some beliefs or traditions believe that having a lover's hair can bring good luck, protection or increase strength.

In some cultures, keeping hair may be to commemorate a dead person or an important moment. If one of two people has lost his hair for a while, keeping one hair may mean that they want to remember the emotional connection during that period.

4. Another possibility is that your boyfriend only keeps your hair for personal preference or emotional reasons, which has no special significance.

Whatever the reason, if you want to know why your boyfriend keeps your hair, the best way is to communicate with him directly. By asking him, you can understand his real thoughts and feelings, thus establishing closer ties.