"Be yourself. People don't have to like you and you don't have to care." - Jeff Bell
I wish I had learned this when I was a teenager. Or even when I was 23 or so. I didn't always realize the strength in myself, but it's something I care about other people seeing in themselves.
What do I mean? That *thing* that you think is a deficiency might not really be that bad. You might see it as a weakness, but if God's strength is really shown in the midst of our weakness, our weaknesses aren't something to run from but rather something to embrace.
This doesn't mean find the "worst thing about you" and exploit it. Rather, it's that personality quirk or the thing you think others have that you lack. If you needed it, you'd have it. If you will need it, you'll learn it. And if it seems like something that would be helpful that just doesn't exist within you, God can make up for all of it - and He's not surprised but probably quite glad you're trusting Him instead of relying on your own ability.
Me? I'm too blunt. And too quiet. Which means I don't talk much but when I do I ask the question no one should really ask. But it's a weird gift. I listen well, am quick to get to the heart of an issue, and care too much about people to waste their time. And embracing that, I've gotten what I've needed and somehow managed to encourage others as I'm going. I don't know. My "weakness". God's strength. It all just works out when my base assumption is that God isn't surprised by any of it.