If I knew… I wish I knew

Why do you need to know 'If I knew…' and 'I wish I knew…'?Both of these phrases are used for something we don't know but realize things would be easier or better if we did. These are called 'conditional' phrases and are used to talk about what we do not know. We use these phrases to talk about what we would do IF we had certain information. However, we don't have this information.