<b><i>Introduction:</i></b> Autism has typically been characterized by its external manifestations rather than experienced phenomenology, with consequent impacts on both research and practice. There have recently been increasing calls for more phenomenological enquiry in autism, but little actual work reported. <b><i>Method:</i></b> A shared participatory phenomenological self-investigation was conducted, by the four authors, of lived experience across the autistic/non-autistic divide. The sample size was chosen as necessary for the feasibility and acceptability to participants of such work in this context. Roles of “researcher” and “interviewee” were purposefully alternated between participants to establish trust and reciprocity. Initial phenomenological reduction or bracketing was applied to the description and recording of each participant’s intimate lived experience in a number of key domains across social relationships, the physical environment, development, and in adult life. These experiences were shared within dialogue to open them to investigation and questioning from the others, with alternating interviewer and respondent roles. A third step synthesized these shared observations across individuals into themes of continuity and difference. <b><i>Results:</i></b> A number of emergent themes, such as the need for trust and reliability, and the impact of context on regulation of emotion, sociability, and empathy, showed striking commonalities between all participants. Other themes, such as primary sensory experience and social joining, pointed up more clear differences between autism and non-autism in development and the adult world. Themes of interest-focus and attention were marked by both commonalities and difference. <b><i>Conclusions:</i></b> This shared phenomenological method was taken as a first step within a new area of active investigation in autistic phenomenology. It proved successful in eliciting detailed information on self-experience. The results suggested hypotheses for a new understanding of autism within the wider “human” spectrum of experience; for instance, the common basic need for trust and social connection but striking differences in sensory experience. It suggested that some characteristics long thought intrinsic to autism, such as social mis-perception and reduced empathy, may be alternatively understood as state-dependent outcomes contingent on specific contexts and interactions. Implications are suggested for testing in further research, developmental theory, and intervention practice.