When my oldest son, Billy, moved into his N.C. State University dorm room a few weeks ago, his roommate's mom and I found ourselves in the odd role of being a visitor in our son's room.

We wanted to stay and help organize things, but it became clear that the guys wanted us to leave. This was their turf now.

No matter how cool you ever were before at home, no parents -- nor their advice -- are cool at college.

One mistake I made was buying an erasable memo board for Billy to hang outside his door.

He pulled it out of the bag and asked, "What's this for?"

"When I was in college," I explained, my voice filled with the wisdom of experience, "everybody had memo boards on their door so if someone came by and you weren't there, then they could write a message that they had stopped by."

I looked over at Billy and realized he was trying to politely suppress his laughter.

I was obviously a source of amusement for my child. "What?" I asked, defensively.

"Mom," he said, smiling broadly, "now we just text each other."

"Yeah, but," I started to reply and then stopped, knowing I had no response.

Yep, there had been some advances in technology since I was in school.

"Well, it was always exciting to come back and see if you had a message on your door," I told him, defiantly. "You're missing out."

"Do you still have the receipt?" he asked.

While doing my back-to-school shopping, it was so obvious which moms had daughters leaving for college and which ones had sons.

The ones with daughters were discussing towel colors and room décor.

The ones with sons were by themselves, wearing forlorn faces, buying the bare necessities.

I made another merchandise drop from Bed Bath & Beyond and Target.

Billy was impatient. I went to the laundry room to see if the washer only took quarters or if it would accept his ATM card.

I discovered it would only take quarters or the special campus card, but not ATM cards.

I attempted to share this with him, but he cut me off.

"OK, Mom," he said with an exasperated glance.

I offered him some quarters, but the look got more exasperated.

It was time for me to leave.

A few days later, my husband called Billy.

Billy was walking to Hillsborough Street to get quarters because his dorm office and the student store turned up quarterless.

To his credit, he apologized for not listening to me.

Ah, sweet validation.