Thought I'd toss in a few words as someone who grew up with ADHD.
I'm Canadian, we have two school systems - Catholic and Public. I was diagnosed with ADHD in second grade, sometime, I assume, around the time I got kicked out of the -entire- Catholic school system in my city. Apparently I had tantrums so extreme no school would take me. I had to switch to public school for the rest of the year. By the next year, third grade, I was medicated, in a new catholic school, and seeing the first signs of the joint problems that plague me now.
I remember those years in vignettes, mostly, stories I've recounted to myself often enough that I remember the retelling as much as the memory. First days of school, punishments, rewards, birthdays, and the endless repetition of the after school afternoon.
I don't remember feeling any change, or school getting any harder or easier, or feeling like I was made any different from the medicine. The tough things were being the only new kid in my class, or having legs that randomly weren't supporting me.
I've always been obsessive and strong willed, where as ADHD makes me think of being distractable. I could pay attention to the same thing for hours - it just wasn't what I was supposed to be attending to. I know I must have fidgeted a lot - some phrase with 'minor motor system' was bandied about at lot. But now when my hands are restless I put them to keyboard or pen and paper. I don't remember having much of a temper either, but I know I got wrestled to the floor a few times when throwing a fit about not wanting to take that little white pill. My report cards for those years are filled with comments about applying myself and writing legibly and "Laura really needs to stop reading in class". The reading in class comments I was still seeing in high school, actually.
In fifth or sixth grade or so, I think, I was taken off ritalin. I don't actually remember the medication being stopped - it wasn't a big deal to me.
What my mother remembers is quite different. She describes those years as watching me rebuild my personality from the inside out. For her, the medication made an absolutely drastic change, and it's something she's never regretted.
As an adult, I find it hard to look at myself in the light of ADHD. I don't think of myself as a person with a learning disability, or say 'I only do X because of ADHD'. I have days where I'm less able to concentrate, less productive - and days where I can block out everything and get an amazing amount of work done. But to me that's my personality, not something I was diagnosed with as a kid.
I would recommend you check out a great (if somewhat old ) book on Adult ADD called
You mean I'm not Lazy, Stupid or Crazy?. For both myself and my brother - who had a milder case and was never medicated - it really hit home and described the experience accuratly.