Can you read the sign

The sign said "watch for pedestrians." Innocent enough but the sign was on the side of Interstate 5, a multi lane Interstate that begins in Washington St. and Ends in San Diego, Calif. At the point when I saw the sign there was at least eight lanes of traffic.
Who would be crossing here, I thought. It made no sense to me. I found out later why the sign was there. Mexicans crossing the border. A pictorial version of the sign cleared it up for me.
But signs can be difficult to read. Especially signs of a physical nature.
When I was in high school I never understood them. I sucked at reading my friends, peers, individuals of the opposite sex. I was oblivious. I am not sure why really, but I was. I just didn't get it. I didn't understand why this one young lady liked to hold my hand, or this one wanted to be around me. I didn't get it. That took a while to figure out.
But now as an adult I think I am in a similar situation. My oldest son, who is 10, is showing signs. Signs that I either don't understand or am flat rejecting on principal.
Recently while driving my wife to Denver, my son became upset. Apparently someone at school had said something to him and it was bothering him still. He refused to talk to my wife and I and withdrew into himself.
I finally figured out what was going on and we worked through it. But on the way home he became reclusive again.
I don't know why. I tried to talk to him, tried to keep the conversation light. I focused on the things I know he enjoys, even offered to let him choose the music we listened to (a big deal in my family), but nothing worked. For more than an hour he sat across from me and didn't talk.
I think he was upset that his mom was gone. My wife took a trip to Washington St. to see family. But I think he didn't want to show it.
I am reaching an age, or rather my son is reaching an age, when it is not as cool to talk to parents. I have always expressed to him that he can talk openly to me, and until the last few months he has.
This is a sign I think I can see clearly. My boy is growing up. So I guess now all I can do is show him that I am there for him. And take every opportunity to be involved with him as possible.