1. What do he following words have in common?

ALL
BALL
BIG
ROB
TAR

2. The following phrases have something in common that has nothing to do with their meanings. Can you determine what it is?

You've got mail
One good turn
As time goes by
Miniature golf
The golden rule
Idle gossip

HINTS:
#1: The same two letters will change each word into a new one.
#2: It has to do with being self-centered.

Answers:

1.  Each word can be followed by OT to make a new word:

ALLOT
BALLOT
BIGOT
ROBOT
TAROT

2. Each phrase conceals the word EGO:

you'vE GOt mail, etc.

Credit #2: 
Arlan and Linda Bushman
SELF-CENTERED