They make no sense at all,
In them you either fly or fall.
They make you do it all.
Their need is biologic,
but they are most illogic.
They are not real but still can be achieved,
If they are just believed.
Answer: Dreams.
This riddle appears in the following downloadable PDF files:
Can you solve one of the most famous logic puzzle ever?
Memory Matching game for kids, adults and seniors.
Connect the matching tiles and pop them all.