Challenges with writing words

I've noticed that sometimes when I'm writing words that it takes me a little longer than it used to. I seem to need a little time to think and then form the letters. This is when I'm printing because I don't prefer to use cursive because it takes even longer. Also, for some strange reason when I write the number five, it can look like an S if I don't take my time and really concentrate and think about it. I have also noticed that sometimes when I make mistakes while doing Sudoku puzzles, it is because I don't recognize that some of the letters or numbers have already been put in. This is very strange for me because I used to be really good at solving these puzzles.