How quick does sourdough bounce back? Or does it?

I've been neglecting my sourdough.
Left it on the counter for a week and completely forgot about it a couple times.
Re fed it yesterday.
No growth though. :(

How quick will it bounce back?

How warm is the area it is in? How wet is it? The warmer and wetter the faster it should come back, though it may get taken over by "bad" yeast. I've never had that happen but hear that it's an eventuality, at least according to some books

House is usually 17-19 degrees.
It looks as though it should be wetter than it is. I might have to add some more water.
I fed it yesterday but it doesn't smell as sour as it should and it's not growing and falling like it usually does.

You could also try taking only a little of the lazy sourdough (like half a teaspoon) and then feed that in a new jar. Maybe the residues of the old sourdough slow down the startup.
Some people add a little honey to a lazy sourdough, but I have not tried it myself.

What I would do in any case is put the jar over/under a hot water bottle, wrapped up in some towel for several hours. The ambient temp might be too low.

I let my sourdough get neglected all the time. Pour off the liquid, dump out half, feed. Try it again. Sometimes mine takes a few times before it stops being grumpy. (that said- my sourdough is crazy, I keep it in the fridge and it is still very active in there!)

If your sourdough is weak and not contaminated, you have lots of options. Here are three more tricks that can be combined or tried in succession to add more natural yeast to a weak starter:
1) Use 1/2 c rye flour in your starter instead of wheat
2) Put 1/2 c rye berries in water over night and use the soaking water
3) Put 1/2 c organic raisins in water over night and use the soaking water
Add the soaked rye berries to your bread. Add more water to the raisins and let them ferment a day or two longer. Add the fermented raisins, walnuts and a couple of teaspoons of cinnamon to your bread (sweet, no sugar needed).
Enjoy!

I've killed sourdough several times by leaving it out too long. Currently I am not keeping a sourdough (after 6 weeks away and I could only ask the housesitting housemate to water the garden and keep up with other essentials, so I didn't ask him to feed and tend the sourdough).

I've been getting very nice results from making bread with only a tiny amount of commercial dry yeast and very long rise times. It comes out tasting much like a decent sourdough bread.