No, not everyone is meant for a serious relationship.

Some people prefer celibacy, for various possible reasons.
Some people prefer only casual sex but no emotional intimacy.

What matters is the quality of your character.

Are you honest with yourself?
Are you honest with others?
Are you responsible not to spread diseases everywhere?
Are you responsible not to have an unwanted pregnancy?
Do you respect your partners and always tell them upfront what to expect?

Those are the things that matter.