Three professors had walked down to the train station from the University. They were so absorbed in their conversation that they didn't hear the train arrive, but they did notice the noise of the train as it started to depart.

After a desperate rush two of them manage to scramble onboard. The third looked sad and a passing railway official said,

'Don't feel bad, atleast two out of three of you made it.'

'True…', sighed the professor, 'But the other two were only here to see me off!'