WARNING: Profanity and vulgarity (NOT suitable for any age)!
There is a myth that the Buddha and therefore Buddhists are and always were Hindus. Only Hindus say this, of course, in spite of the fact that the Buddha opposed the authority of the sacred Hindu scriptures (Vedas) and the traditions, sacrifices, and customs of the brahmins.
The Buddha, a wandering ascetic unencumbered by Temple politics, taught a path that did not depend on intermediaries for "salvation." He made known the liberating truth directly visible here and now. Practitioners penetrated it and directly experienced its benefits immediately. It is said of Buddhist teachings that they invite one to "come and see."
Hindus have done the same to Mahavira, the founder of Jainism, ignoring his teaching by holding him in high esteem for his severe asceticism and support of basic Brahminical beliefs (regarding the soul, karma, the afterlife, and the role of self-mortification in spiritual purification).
Sadly, while it seems like a compliment, brahmins explain away his contrary views in all seriousness by saying that "God" in his incarnation as Vishnu was purposely trying to lead people away from the "eternal truth" (Sanatan Dharma) of the Vedas and Hinduism.