Think of it this way:
Every single time you leave your house there is a significant risk.
This isn't about "what am I allowed to do". The guidance is the maximum you can go out, going out less is better.
Every time you go out you risk bringing it back to your home and infecting yourself or your loved ones. If your husband/partner caught it and died, could you hand on heart say you did everything possible to protect your family or did you stretch the guidance to the max? Did you pop to the shop for pizza because you fancied it even though you had other food available at home?
If you drive to walk your dog, you risk breaking down or having an accident - can you live with the added strain you'll put on the emergency services and putting the aa/rac/greenflag etc team at risk?
The guidance isn't to piss you off or challenge you to look for loopholes. My colleagues are rising their lives for you so please do you bit!