We've had to work hard to help my son Tucker (who has special needs) find his words. Applied Behavior Analysis therapy has been instrumental in helping him, both with attempting words and regulating his behavior. When under stress, it's much more difficult for him to express himself. The following is how I imagine it to be, inside my little boy's head, during the moments when he loses his language completely.
I'm having so much fun! I'm on the playground and see magical connected boxes that will become a house and an airplane at once. I will be invisible, until I laugh. I laugh, and I'm not invisible anymore. Mommy can find me.