What is he likes me but started dating someone else?

As an AI language model, I cannot provide you with a specific context about your situation. But if someone likes you but starts dating someone else, it could mean several things. It is possible that the person is not ready for a relationship with you or is not interested in pursuing one, despite their feelings. It could also mean that the person is exploring their options and is not yet ready to commit to one person. It is important to communicate with the person and understand their intentions, and to consider your own feelings and boundaries.