It is quite difficult to say as we are trying to piece together the complete story from 500 BC. We are also working with imperfect sources. It is at least easier to do this for the Buddha than it is for Christ (who, though he lived around 0 AD, has even fewer reputable sources we can use to derive information on the historical person).
From what I remember, it sounds like he had an out-of-body experience or something similar early in his journey. If I recall from the suttas, he gives the names of two teachers he followed early on and with them examined this experience. Then, there's ANOTHER sutta where he explains ANOTHER path he pursued. In this sutta he tells the story of when he was young. In this story, he sat peacefully & serenely under a tree next to a field, and here in his youth he felt the experience of joy. This joy is what he narrows in on and values as a manifestation of the jhanas- the self-arising joy that is a product of mystic transformation.
I know Jeff and the others here are major advocates of the jhanas, but having studied them in detail I confess I still find them very confusing and unclear. The distinctions between "jhana 1," "jhana 2," "jhana 3," etc are not specific or concrete enough. I do feel Jeff's translations of the Pali words is the closest approximation to what the early Buddhists were getting at. However, I prefer the model presented by Teresa of Avila in Las Moradas, where she explains progress in the mystic life as part of a larger unfolding life-process, that involves personal struggles as well as the contemplative life, and culminates in the state of self-perfection.