The dreams we most likely remember are the ones that we have just before we wake up for the morning.
These are the dreams involving the mind trying to get rid of something. It could be stuff you no longer need or worries that you are trying to get past.
The first dreams of the night are your mind working threw the things you have learned or seen that day to choose what needs to be remembered an what does not.
Whats goes on in the middle of the night are the things that you really think about an care about long term.
The last two are not usually remembered unless you wake up in the middle of them.