If the password is long and uses a lot of characters, it be harder to remember, which leads to it being written down.
Not really. Think of a phrase and use an algorithm.
(leaving spaces for clarity)
Mets Rule Yankees Drool are 20 characters - that's pretty strong in and of itself
substitute $ for s, 3 for e, and 0 for o and you have
met$rul3yank33$dr00l is easy to remember, easy to type and is pretty damn safe.
If you do something right once, someone will ask you to do it again.