Even if I set the router to static?
Yup, your router doesn't get to choose the IP it gets.
wouldn't setting a static ip on the router, manually inputing the numbers, if the isp forces another ip, wouldn't I not be able to surf?
That's correct. So right now, it's just luck. If your ISP assigns your IP address to someone else, your connection will break.
Entering a static IP on your router does two things:
1) Your router will attempt to negotiate that IP address with the other end.
2) Your router will use that IP address no matter what the results of the negotiation.
Your ISP will likely give you the IP you asked for if it can. This prevents brief interruptions in connectivity from causing IP address changes. (Most modems/routers will first ask for whatever IP they had last, if they remember it. But they'll accept whatever the ISP offers after that.) However, if someone else has "your" IP address, they won't be able to give it to you and will offer you another IP address. You will reject that IP address, and the link negotiation will fail. Your router will retry the negotiation periodically.