I've been lifting hard and consistently for 12 years. In the last year I fell extremely ill and haven't been able to weight train. I've lost about 20 lbs of body weight and my bench press is down 80 lbs from where it was a year ago. I'm starting to feel well enough to lift again and I can't believe how weak I am.
Anybody have a similar experience and bounce back quickly? I'm hoping that a good 3 months of consistent training and eating can get me back close to where I was, but I'm not sure if I should expect it to take longer. 
It's happened to me a few times. I had surgery a few months back after I punctured my hand with my trusty bench made knife, and cut some nerves and an artery in my palm. I didn't gym for like 6 months, lost about 14 pounds or so.
I recently went back, and I started slow. I was beyond sore as shit the first week or two, but I feel great now. I think the key is to start slow, and remember we are lucky as we already have the routines down pact and the correct form for the exercises IMO. Different than a complete noob going in there and trying to figure out how to deadlift. I think once you get a good rhythm going you'll bounce back quickly.
My muscles have horrible amnesia , seriously tho 3 to 4 months should be plenty of time to get your numbers back