The preparation - endless hours and it never feels like enough hours. Both include several pre-*big*race mini-races; (presentations and publications would be like club/state races)
The food - race time is when you get to eat all the high cal stuff and guess what happens when you work on a computer 10 hours a day.
The stress. Almost impossible to think or talk about anything else. *Beware* this can get you in trouble if it appears you aren't listening to those around you.
The daily rituals are very similar come race time wake up, dawdle, eat, dress, dawdle, check equipment, dawdle, warm up, get going, sprint, worry you aren't going to make it, slug it out, cross the finish line, shower, eat, relax, sleep. Then you repeat * 42
The major difference between the two being fitness - one goes up, the other goes down.
Better cross the line soon so I can get back out there!