J.Lo is most grateful for her fans. The singer recently got emotional during her latest visit to Jimmy Fallon, looking back on a heartwarming experience she had with a fan. MORE: Jennifer Lopez just carried Duchess Kate's handbag of choice – and you can have it tooWhen Jimmy asked her if she remembered any memorable signs fans have held at her previous concerts throughout the years, the star was quick to answer that there were "so many."Though J.Lo appreciates every single one, there's one in particular that had her holding back tears as she described it to Jimmy.WATCH: J.Lo celebrates special anniversary at her Bel Air homeMORE: Jennifer Lopez reveals 'surprise' update ahead of Valentines Day with Ben AffleckThe triple threat admitted that though she had been singing and performing for years, it wasn't until later in her career that she went on a "proper world tour." The long awaited tour came when J.Lo was in her 40s, and it couldn't have been more special.She looked back fondly at a sign she saw and could never forget.