This happens to me all the time. My Gmail is first name and last initial. I'm not sure if the burden here is on Google or those sites that don't verify email address before sending stuff like this, though.

The most fun so far for me was when someone used my email to sign up for Ashley Madison (the affair dating site). Of course, they were compromised a few years later and someone built a tool allowing you to search their users by email. Guess who appeared to be having an affair then? Tough one to explain to someone non technical...