Having an uncommon strength or weakness can make you stand out from the crowd, helping to define who you are.
It gives others insight into your unique traits and capabilities that they may not have known about before meeting you.
An uncommon strength or weakness could give a competitive edge in certain scenarios, such as job interviews where employers look for something special within candidates which sets them apart from other applicants.
Developing and honing strengths which are rare can provide more opportunities than those with common abilities because of their scarcity value alone; this is especially pertinent when applying for jobs or internships etcetera that require these skillsets specifically.
Having an unusual ability could also be seen as inspiring by those around us - it shows we're capable of achieving anything despite any disadvantages we might face due to our ‘uncommon’ trait(s).
Finally, having both strong points and weak points helps us learn how to better manage ourselves over time so that even if things don't go according plan initially at least there's something else working towards success in the long run.