I have seen a lot of the plight of those who tried to keep a day job, but also make a success of paid gigging as a sort of hobby; but got too successful at that, so that they would be off on gigs 3 or 4 nights a week, often at a distance, getting home late but still having to be up for work next morning. So they would be often caught in the trap of not making quite enough from the gigs to equal the earnings they would be sacrificing if they went full-time, to maintain the lifestyle they had built up for their families; but unable, thru tiredness, to bring the effort & commitment required of them to discharge their daytime duties properly, in a manner which would not let down or disappoint their colleagues, or others dependent [pupils, e.g. -- they were often teachers]. At some point a decision had to be made.

~M~