My 9 year old cousin said something that made me reflect and feel bad

Im 14 years old and my cousin is 9 and Im babysitting him and he's low-level autistic and I was reading and he was watching his tablet and he walked up to me and said 'thank you for not being mean' and I thought back to all the times he visited and I realized I haven't even been nice, I've been very short, impatient and mean to him because I see him as "annoying". I apologized to him and Im now being more patient and trying and showing him attention, because for a minute I thought 'I'm treating him like how those in power tend to treat us (women, ppl of color, the autistic etc)' and I don't want to be like that, I want to treat him like a person who deserves my time and attention but it's hard when you have to 'babysit'