As unexciting as it may sound, one of the biggest challenges I have at work is how to find time to sit down with people at work and talk.
Thing is, people's diaries are booked off for days and days and so even getting 4-5 people together for a few minutes is a big task. Example:

The causes? No idea. I guess it's a combination of little delegation, too many meetings, to long meetings, poor time management in meetings ... whatever it is, everyone seems to be busy meeting everyone else, all the time!
I am trying all sorts of things to get around the problem (keeping my meetings short and organised, meeting few people separately instead of all people at once, scheduling meetings early in the morning) but I have a feeling the system is still winning.
And then I wonder: if the people I am trying to meet are this busy, how must the diary of someone's really important look like? (Barack Obama, Mahatma Ghandi, you name it).