I have a full time job as well and do not have the time for pet projects. After work I get home and have some family time until it's bed time. Then my wife watches some TV while I work for about 1 hour tops.
As you know, 1 hour is NOTHING when developing. I take at least 45 minutes to get into a groove and ultimately I do nothing of substance.
I envy single people in that regard, they can work until their eyes drop out of their head. Don't waste your time! You hear me single people! Don't waste your time!