Some people truly are quick studies. They’ll absorb what you give them, understand it, and then run with it. It’s a remarkable gift that makes them assimilate into new teams faster than most.
Whether you are one of these people or not, adding “fast learner” as a line item in your list of skills doesn’t really hold much value. Employers are scanning your resume for things that make you stand out. “Fast learner” is such a common resume “skill” that all it really tells them is that you probably don’t have the skills that the job opening requires. Best to leave it off your resume… UNLESS…
You truly are a fast learner and dammit you want people to know it. If this is true, then offer a concrete example that demonstrates your ability in action. I’ll give you an example. I do put “fast learner” on my resume, and I immediately follow it up with “Learned new content management system in half the average time.” During my interview, I was asked about it and I was able to give them the full story of how, upon starting one of my previous jobs, I had to learn a rather complicated, proprietary CMS. During a later performance evaluation, my boss told me that their new hires usually took an average of 6 months to be comfortable with their system and do projects on their own. I was able to get to that point in only 3 months.
It sounds impressive, right? If you have examples of fast learning, then by all means talk about it! Put a teaser on your resume so it piques their interest, but don’t spell out the entire story. Interviewers don’t have time to read stories. Although on-the-job anecdotes work best, if you don’t have any of those to share, think of examples in your personal life. Maybe you were able to fix your car using only a manual, or maybe you enjoy putting together Ikea furniture. If it demonstrates intelligence, use it. If you can’t think of anything, then it’s best for you to stick to resume items that don’t cast doubt on you. Instead, talk about qualities that really make you shine.