Mine is a bit different. It wasn't advice or a quote, but a lightbulb moment.
I was trundling along in a difficult marriage, difficult mainly because my husband was earning absolutely nothing for almost ten years in his "business" and yet he kept telling me to give him more time, the big deal was coming. He put me under pressure to let everyone else think he was the breadwinner.
I was skint, on maternity leave, frustrated, stressed and paying for everything as usual and there was no Plan B in his mind. His business was definitely going to work, no discussion allowed.
I met a single mum also on maternity leave and we got to talking about finances. I realised I'd be a bit better off financially alone, and that realisation allowed me to examine the marriage more critically. There were other serious issues.
I ended the marriage. I no longer have to maintain him, just my children, which is challenging enough. He is still earning nothing but it's not my problem to solve any more. I am much happier.
I don't tell the story in real life for fear of benefit bashing (I work full time but received some help with childcare initially as a single parent, something important I realised in the course of the conversation).
And although I ended up quite friendly with that mum, I've never told that the conversation with her she was pivotal in the process of me ending my marriage, in case it made her feel sad/ bad/ guilty/responsible.
You just never know who you're inspiring even in the most mundane conversations.