Even if you're fully vaccinated, you can still get Covid. That surprises some people, but only the people who don't know how vaccines work.
Vaccines work by showing your body some aspect of the virus, so that you're primed and ready when the real thing shows up. Which it will - the delta variant is very infectious.
So, you get infected, your body swings into action. "I've seen something rather like this before, and I know what to do". And before the virus an really take hold, it gets fought to a standstill, and then wiped out. So you get some symptoms, but not too bad, and if you get tested for those, you know you've had Covid. If you're unvaccinated, this happens five times as often as if you're unvaccinated.
But I've had colds before, and I think I had flu once, and it wasn't pleasant, but a couple of days in bed and I was on the road to recovery. The important thing is, not to get ill so bad that you have to go to hospital.
If you have to go to hospital, that's because you've got it so bad, you can't breathe. The oxygen level in your blood falls, you feel like you're short of breath, and it doesn't get better, it just keeps getting worse. So you call an ambulance, and they give you oxygen and take you to hospital, unless the hospitals are full, which can happen in a pandemic, because there are so many other people with the same problem.
Unvaccinated people have 29 times as many hospitalisations as vaccinated.
And that that point, it's too late, a vaccination isn't going to help you. The only thing that can help you is hospital care, and maybe even an intensive care unit.
In hindsight, you should have gotten vaccinated. I'm hearing a lot of people who are in hospital, saying that. Hindsight doesn't help, though. Only foresight helps.