The teacher years.
Eight years of public-school ESE. Preschool, elementary, middle school. Hundreds of IEP meetings where a parent walked in nervous, signed a document they hadn't fully read, and walked out hoping for the best. I sat on the school's side of that table. I saw what got written when nobody pushed back. I also saw what got written when somebody did.
I learned where the legal floors are versus what schools voluntarily provide. I learned which language commits a school to actually delivering services and which language gives them an exit. I learned how the same evaluation can produce very different IEPs depending on who is in the room and what they ask for.
Most of all, I learned that parents who came in informed got dramatically better IEPs for their children. Not because anyone on the school team was acting in bad faith. School teams are stretched, and the easy path is always to write the document that's least likely to generate pushback. An informed parent makes that path harder, and the IEP gets better as a result.