The fingerboard in that post is disgusting! I thought mine were bad but they're nothing compared to that! I tend to wash my hands before playing so I don't mess it up too much but I change strings every month and I always give a full clean at the same time. I should probably wash my hands before playing. I've had the same strings on for over a year , is that bad? If you don't mind it then there's nothing necessarily wrong with that. I just find I love the feeling and the sound of brand new strings. I only use Elixir strings which most people are happy to leave on for months but I start to notice a loss of tone after a week or two. There's nothing nicer than the feel and sound of new strings to me :D One thing to be aware of is that your fretboard can dry out from the sweat, gunk and general humidity so it's worth restringing just to keep your fretboard feeling fresh.