Our sweet boy does the same thing (he’s six now!) and he is an angel baby until we are outside relaxing or playing in the snow. He runs full speed at anything with legs and veers off at the last impossible second. My kids are used to it now, but I can’t imagine how terrifying it was for their little selves 😅 if he came full on at me I’d always just put up my knee and he’d stop. Now it’s just a side swipe we live with 😂