I too find myself absent minded and a little scary behind the wheel of a vehicle. Thankfully most of my business is close to home.
I suppose chemo brain is likely since he's been getting dosed since March. No telling when it will stop.

CG to my husband, Matt. Dx June 2009 Stage IV Oropharengeal SCC right tonsil primary with distant metastases. Rad to neck- Surgeries to lungs- Every avail chemo - ran out of options Jan 2012, called for hospice help Feb 2012, at rest March 19, 2012.