Because I subscribe to lots and lots of sales trainers, nlp-coaches, etc. in social media I can barely go online without reading "motivational quotes" and usually I have heard the same quotes hundreds of times before already.
And that is probably because they are pretty decent quotes and can have a positive effect.
Hear are two quotes that I really like that I had not heard untill recently. Maybe they can´t be categorized as "motivational" but good quotes none the less: