Is it mine?

This week I've been reminded of something that I've never understood. There are about 50-75 of us at any given time working in one large room and several nearby conference rooms. Cubicle walls are low and plenty of work is being done in small groups. Thus, it can get noisy at times, especially with cell phones and office phones ringing here and there.

Today a cell phone rang a distinctive tune and about 4 people grabbed for their phones. Now, I'm not saying it's not possible that these 4 people had the same ring tone. BUT. Chances are good that they didn't all share this particular tune. So what I don't get is why people reach for their cell phones just because they hear a phone ringing. If it's not your ring tone, what on earth are you doing? I see it all the time and it drives me nuts.