I also said "Light", sometime in my first January. I'd have been about seven months old.
Then I didn't say a word till I was three and a half... My mum pointed out the new moon, and I said, "did Daddy buy it?"
After that I would never stop prattling to my immediate family, and used a very wide vocabulary, but many people still thought I was dumb for ages, because I'd revert to silence in the presence of "strangers." (Like teachers, doctors, neighbours, visiting relatives, etc.) My Dad finally got me over my phobia of public speaking by teaching me poems to recite, giving me newspapers to read aloud. I remember before I started at school, standing on the kitchen table reading an article about Egyptian politics to a room full of gobsmacked friends of my Dad. One guy (who I remember vividly, he had blond seventies hair, and a red seventies beard, with nicotine stained fingers and a roll up dangling from his lip) said, "isn't she just parroting? She can't know what delta means?" I said, "delta is a letter in the Greek alphabet that starts from a narrowish point at the top and goes wider, it's used metaphorically to describe river mouths, because they look somewhat alike from a birds eye view."
I remember a lot of stamping of feet, and laughter, and hairy blokes slapping my Dad on the back.
Recently I asked my Dad about this, and he tells me I was either a week short of five, or a week after five... he can't remember. I started school a week or two later. Apparently after that he and my Mum had a discussion... some of the neighbours wanted to come and watch me "perform", and my Mum was adamant this would be bad for me, and put a stop to it. I think my Dad would have done too... but I do know he was painfully proud of me, having worried there was something wrong with me for years.
It may explain why he's so reluctant even yet to accept my auty diagnoses.