I tip $5-10 every time I order delivery. I do not order delivery unless I am sick or its shite weather and I cannot get my own food. I feel like if you are bringing me necessities in whatever condition it is you deserve to get a fair amount. If it was friends or family I would offer a case of beer, how is it different for a stranger.
I find it normal to leave the minutia of everyday details behind. It takes an effort to commit anything to memory. Sometimes just letting go and not expending the effort is worth it. If you’re missing important details, begin writing things down. Check yourself, your diet, your hydration, and your sleep. Every single one can impact your ability to form memories.