How do I see my brother as not a baby 🤣

So I am 10 years older than my brother. Everytime I look at him or think of him, I see him as this chunky little toddler walking around in a diaper, trying to eat bugs.

He is 13 nearly 14 now and he tried talking to me about a girl and I looked at him seriously confused. Not thinking about the fact that 13/14 year olds are totally into having crushes and stuff. He was like “I’m not a baby aha” and I was like “no you’re not, my guy.”

🤣 but I still see him that way. How do I see my little brother as this young man that now is growing armpit hair and getting crushes and not a squishy baby? I want my brother to be able to come to me for advice and not get confusion