Stay on the phone the extra minute your grandpa always wants. For him, that minute is the whole call.

The two of you are not having the same experience. For you the call is one of many things in an afternoon, and the last minute is the one standing between you and whatever is next. For him the day may hold very little else, and the stretching out is not poor timing, it is him not wanting it to be over.

Next time, decide before you dial that the call ends when he ends it. If you truly have five minutes, say so at the start so the goodbye is not a surprise. One question about something old usually gives him the best part of his week.