In my experience, having a terminal and two or three Leafpad windows open for a few days slows down the phone so mutch that I miss >90% of received calls simply because it takes so long for Phone UI to wake up and start ringing. I have even seen it in action: an incoming call, the screen lit up, Phone UI wanted to start but it took so long (>20 ssconds) that the call was missed. All I could do was helplessly watch it happening.

Following that experience, I have learned to close Terminal and basically everything that keeps undo history (browsers, editors...) every day. Since then, no missed calls.