What! you're not perfect?
You have weaknesses? You've done (or haven't done) things you regret? You are not half as courageous as you would like with certain people or in certain situations? You don't know everything on everything? Oh dear, you're not perfect! And of course, the worst that can happen is that other people may find out!
Many of us spend a lot of time and energy hiding our weaknesses and striving to look perfect so others will like us, appreciate us and respect us.
Well folks, we've got it all wrong!
Not only is this tiring (for us) but it is exasperating for others: there is nothing more annoying than someone who is perfect - or who is pretending to be (yes, because we all know deep down that no-one is perfect). Perfection, or rather its enactment, is a people repellent and makes it impossible to connect (what about you? honestly, do you like perfect people?).
So, the more you pass yourself off as perfect, the less likeable you are. This is good news! But even better news is that your weaknesses can make you absolutely irresistible! Why? Simply because they make you human and allow others to be more accepting of their own weaknesses: you relieve them for a moment of the overwhelming weight of unattainable perfection. They recognize themselves in you, and your honesty makes them feel good and trusting (because it has made their brain release a good dose of oxytocin, the love / trust / social bonding hormone :).
But caution, you must be careful how you share your vulnerability. Remember, your goal is to connect with others, to create a strong bond, NOT to make them uncomfortable. So, please avoid:
lamenting and undermining yourself with a hangdog face: forget the "I'm pathetic", "I'm such a loser" or similar, which will only trigger pity, irritation, or both...
saying you are no good at something (e.g. announcing that you have a terrible singing voice) and then masterfully demonstrating the contrary (e.g. you could win "the Voice") - which will trigger resentment or hostility for having deceived them (yes, they might admire your voice, but they will be pissed off with you)
So, if you want to establish a strong connection and become instantly more likeable, you need to dare (yes, dare, because some of these might feel very risky):
say "I don't know" (like the Dalaï Lama: he is very comfortable with it)
recognize that you are not the best at something
admit you made a mistake
admit you are wrong
ask for advice (and resist saying "yes, but..." ): be curious and grateful - you never know, it might be great advice (or not - remember, you don't have to apply it)
And again, caution: the WAY you say all of these is crucial. Your non-verbal language - your tone of voice, your eye contact, your posture - must demonstrate that you own your vulnerability (as if to say "Yes, I am human, and therefore fallible, and it is OK") and that you admit it with simplicity (no arrogance please, as this is a killer!): be both humble and self assured.
Oh, I was about to forget: of course, sharing your weaknesses must not become a pretext to stop progressing, on the contrary, as seeing someone making sincere efforts to improve also makes them very likeable.