The number twenty indicates that you are in need of support. Perhaps you are feeling withdrawn and isolated. The dream may signify having 20:20 vision. You are seeing something more clearly now.
To receive a love note in your dream symbolizes a budding new love that is blossoming in your life. Alternatively, the dream may mean that you are seeking some reassurance or reinforcement about a new relationship. You are feeling insecure.
To see or write on a post-it note in your dream indicates that there is something that you need to make a mental note of. Perhaps the note is a message from your subconscious. Alternatively, the dream may be a metaphor telling you to go ahead and "post" a message or mail a note.
To see a promissory note in your dream indicates that you need to allow yourself more freedom to do something. Don't be so hard or strict on yourself.
The number 20 in a dream represents conflict with power. Your power or freedom may be turning on you in some way. You may be struggling to get your power back. You may also be confused with which direction to take to achieve power.