How much sleep do you need?
This is probably something that someone contemplating a career at the Bar (or contemplating a career as a solicitor) will never consider, and is unlikely to be asked at interview. However it can have a significant impact.
Whilst not requiring much sleep is probably an advantage in a whole host of occupations, it can be particularly important for lawyers. Sometimes there can be a fine balance between really putting the effort in regardless of the impact in terms of hours and getting to the stage where you have no useful critical analytical facilities left to utilise.
For example as a solicitor you do not necessarily work standard hours. Often relatively junior solicitors will want to be putting in a possibly huge number of hours in order to show how keen they are. It also depends upon the nature of your work and the location. If you are a member of a City firm and lucky enough to be given a foreign posting, then you will almost certainly be expected to be available for at least part of the London office hours. This can tend to be a more onerous obligation for those based in the East than the West. Since often the City firm will want some input from the foreign office before the close of ordinary business hours, that is much worse if you're in the Far East and many hours ahead of GMT then it will be if you are say in the Caribbean so that close of play in terms of ordinary business hours will be relatively early in the working day for you.
Areas of law can also make a difference. If for example you are working in mergers and acquisitions then if you are in the middle of a deal you will be expected to carry on regardless. Part of the team will not be expected to up sticks and go home before matters are completed.
This can also be unfortunate for those involved in trying to thrash out the terms of a contract. I recall one very good solicitor, who had moved to a relatively small firm but had a very good quality niche practice, turning up to negotiate the terms of a contract and finding himself up against a team of four. The bare bones of the deal had been agreed, but there was a deadline and trying to get it into appropriate legal language was quite a complicated task. He negotiated with the team of four on the other side until about midnight. Imagine his surprise when a different team of four took over at midnight (having been kept in the loop by the others via electronic transmission) so that he was then faced with having to battle on against a group who had arrived well refreshed. He managed to cope, but if he had said that he could not carry on and in consequence his client lost a lucrative sale no doubt the solicitor would have been the one taking the blame.
It can sometimes be a thankless task. I was once undertaking a case in Birmingham and caught the train back before embarking on what was going to be a difficult cross-examination the next day. I was returning on the early morning train. I arrived home to find that a substantial set of papers had been dropped off for me to undertake certain complex drafting work, requiring the papers to be returned for the following morning. This was impossible. Someone else would have to do it. That was until I noticed that the instructions told me that a debarring order had been served against my client which meant that unless the relevant document was properly finalised so that it could be served the following day, the client's substantial claim would be struck out. I therefore had to work all evening until 3 AM. I then went to bed for just two hours, had a shower and shave, and then did an hour of work just refreshing my mind as to questions I was going to ask that day before setting off for the train at about 6:30. I would bet if you asked any barrister you will find that he or she has had to put up with various days like that. I even know of one barrister (now a Judge) who had to work late into the evening on the night before her wedding, because as she had left Chambers her clerk had rushed over and instead of wishing her every happiness for her future as she had imagined, he gave her a set of papers, said they were urgent and said he had made arrangements for one of the guest to collect them from her at the wedding. Despite being a very formidable individual, on this occasion she was so speechless with astonishment that she ended up accepting the papers without complaint.
Before going on a recent trip I received some urgent papers the day before. In consequence, instead of finishing at about 4 PM, I had to work into the evening, went to bed at 11:15 PM, set the alarm for 12:40 AM, worked until finishing the papers at 8:15 AM, had a 15 minute nap their shower, got dressed and took a taxi to the airport.
If therefore you're one of these people who is completely trashed if you do not have a proper night's sleep than I would think long and hard about coming to the Bar, and be prepared if you become a solicitor in certain areas of work for similar treatment.