Electric guitar weakness?

Ok is it me or is it a weakness with guitars. It's happened on both my old and new one. It seems that the soldering for where the Amp wire plugs in has broken again so the copper cable which sends the frequency down it has basically broken off and needs re soldering. Now it's an easy fix, but it's just a pain in the ***. Does this happen to all guitars? It's not as if i don't look after it. Every month i change the srtings and polish the fret board. Also after i've used it withough fail, it goes into it's case. let me know if this is usual?