You are an insecure or a person lacking in confidence if:
1. You always compare yourself to rich people, and feel you are the poorest of the poor as a result.
2. You see famous celebrities as gods, and you a mere invisible fan.
3. You negatively poke fun at famous celebrities and public figures.
4. You verbally make fun other people for their accent, their grammar.
5. You get mad when other people turn the table around, they make fun of your accent or grammar.
I have wrote the above based on my own experiences and observation on other people.