Past three private students
These past few years has been almost fun for me and hope the same for my previous private students!  I won't mention names because of privacy terms but can explain some of the issues and happenings.  The first student, I will call was about 13 at the time I started teaching him.  He stayed with me almost to the end of SLT form and then had to leave due to school pressures and grades, etc.  He was a quick learner though and was especially good at catching onto drills.  He did know SLT by the end of his journey.  I mentioned to him and his Dad that he could move on to another level (with a new teacher) when he gets older and wants to continue.  I probably will not still be teaching then.
The next student, I will call Karl.  He was a bit older but still in 20's.  He had to travel some distance for lessons so I knew he wanted to learn.  He did stay about six months but had money problems and was unable to continue.  He had some physical problems from birth and was unable to get his elbow in center which is a big problem when attempting to learn Wing Chun.
The last student I had wanted to learn but just did not have the money.  I will call him Tony.  He only stayed a few months.  He probably didn't need WC though.  He was already a black belt in Kenpo Karate and seemed to know it well.  He had also been in the Army and had fight training from that, so was well versed in fighting methods.  He lived about 30 minutes away from me.
Not sure if I'm going to take on new students anymore.  If I do, I will probably have to insist on getting a certain number of months paid up front.  That way, it will be worth my time for lesson planning and having to stay at home on Sunday's--because a few times, students did not show up.  I would have been waiting all morning if I had not called to check on reason why they were not on time.  A true Wing Chun student just does not do that!  A major tenant is integrity!