What are cellphones for, anyway??

So I wrote an SMS to my girlfriend in the morning. One of the kind that doesn't actually require a reply, like wishing her a great day, telling her that I quite miss her and stuff. I think it was around 10:00. I didn't get a reply, which wasn't tragic as I said. Instead she called me in the evening at around 8:00 PM (20:00 for non-US-citizens). A part of the conversation went like this:

She: "Hey hun, I love you too!"
I: "So you got my message this morning?"
She: "Of course I did. Sorry I didn't reply, I just read the message a minute ago! I was shopping with my mum this morning."
I: "Well... where was your phone?"
She: "At home. On the nightstand."
I: "Why'd you leave it there?"
She: "Those annoying ringtones are so embarassing when your phone rings loudly."
I: "Yeah well, do it like I do: turn off the ringtones, turn on the vibrating alert."
She: "Yup, I might do that."

So then she actually did that. No more calling her nightstand, yay! Confident that I could call her, I dialed her number because there was something I needed to talk to her about.

I waited... and waited... and waited... and waited... and hung up eventually.

That evening a part of the conversation went like this:

She: "I'm sorry, I saw you tried calling me today?"
I: "Yeah, I did! Didn't you take the phone with you this time?"
She: "I did! But I didn't notice you calling."
I: "So you didn't feel the vibrating alert?"
She: "No, I didn't. I had the cellphone in my handbag, so I didn't notice it."

Not... quite... the place to keep a phone with vibrating alert, I'd say...