I confess to developing sloppy punctuation habits when emailing, or posting in this forum. Usually it's because I'm in too much of a hurry to get my twopennorth in before the topic changes ! I just love a line of dots............they can stand for almost anything. If I'm writing a proper letter, which I do, surprisingly often, then I'm very aware of punctuation.
I remember being taught that you should use a colon before a list of words, i.e These people are members of our forum: 3B, T , Viz, etc
A semi-colon is to join two sentences together. That's 2 sentences which could be separated by a full stop (period to you, Threeb!) i.e I don't have a problem with apostrophe; the apostrophe has problems with me.
Having said that...............I rarely use either!