Dr Brewer explains this as follows: ‘You cannot do two opposite things at one
and the same time; you cannot exhaust your energies in one direction, and yet
reserve them unimpaired for something else. If you go to bed late you cannot
get up early.’

> ‘I’ve got to get this ironing done,’ said Mrs Mills.

> ‘But it’s after midnight,’ protested her husband. ‘Far better come to bed,
and do the ironing in the morning. Burning the candle at both ends isn’t good
for you.’

##### See also:

* A door must be either shut or open
* No man can serve two masters
* You cannot have it both ways
* You cannot have your cake and eat it
* You cannot run with the hare and hunt with the hounds
* You cannot sell the cow and drink the milk
* You cannot serve God and Mammon