What is the meaning of intrapersonal skills?

The prefix "inter-" means between two things: international flights are between two nations; interdepartmental memos are between two departments. Interpersonal skills are skills which are exercised between people--communication, etiquette, and so on. The prefix "intra-" on the other hand means within a single entity. Intrapersonal skills are those exercised within yourself, perhaps encompassing imaginative or thinking skills.