Can I join? Though I defied
my speech impediment when I was fourteen. Here is my story.
I had rhotacism, Czech style, meaning I couldn't pronounce r and ř. It's fairly common, other problems being s (when pronounced as "th") or l ("dark l").
There was always some teacher at my primary school who was designated to deal with speech impediments, but it was not very useful. Except I always felt very uneasy and sometimes even embarrassed when I was sent to practice with them. I also learned a couple of little poems with R everywhere in it. And my brothers had a cool new way of making fun of me by repeating td-td-td-td. It's indeed the first way of trying to pronounce tr-tr-tr as Czech r is an alveoar consonant like t and the sounds are produced at the same spot.
When I was fourteen, my mum decided I should try a real professional. Surprisingly my doctor was against is, telling us it's now a part of my personality. Nevertheless, I was sent to a phoniatrist who said there is no problem with speech organs and she sent me to a speech therapist. I had an appointment every week and one winter did it. People would have never guessed now. I also have a perfect French r in my repertoire of consonants. :-)