I have two sons, 8 and 6. Both are summer born, birthdays in mid July. DS8 is lovely but hard work in a variety of ways, he's an anxious, sensitive kid, but also loud and energetic.
His younger brother DS6 had an appointment today that we all had to go to as DH was working. It was already stressful beforehand as DS8 was shouting most of the morning (just making sounds at the top of his voice AAAAH OOOOH BA BA AAARGH OOH etc) BUT he was playing Lego as he did it, and as he rarely plays with toys I let it be.
Anyway we had to wait in the waiting room for awhile and he was crawling on the floor, being quite loud, crawling under the seats and flopping around. I felt like I was telling him to stop the whole time. We played some games like rock paper scissors but basically it was just boring and not much I could do. However during this DS6 largely sat on his chair, swinging his legs and chatting while I continually asked DS8 to sit down, don't go behind that desk, come out from under the chairs etc.
I don't know if my expectations are too high or if this is starting to be unusual for a child of his age. I'm erring towards the latter due to his brother being able to sit fairly patiently. But then I think well there's a range of 'normal' development in younger children and babies and maybe this is the same and what I've described is not all that unusual?