One of the greatest shocks I experienced after relocating to the States was having people ask me to repeat myself because they couldn't understand me.
"How is that possible?" I would wonder. I could hear them clearly (yes some accents take more effort than others but they were OK. Was it an "effort" issue or was my accent so strong that no-one could make out what I was saying?
In no time I was obsessing over the thought that people could not hear me or that I sounded weird. So there I was, in my mid 20s, post-college, post-major milestones plus engaged. As in, an entire adult, doubting something as basic as my ability to communicate with other earthly beings.