Electrical issues

A few times in the past few months my car did not want to start and out of no where there will be no lights not anything. Then after a few times the cars lights come on my horn goes off and the car locked the doors soon after this happens a few more tries and the car starts. I have to give it a bit of gas after this but it will start. I have had the battery, starter and alternator checked everything was good. But today the car was working fine all day then when I got off work went to my car and nothing again no lights no start nothing. I tried for about thirty minutes once in awhile the car lights work come on for a second then shut right back off and I heard a tick sound. Sounded like it came from my dash. Finally someone jumped my car and it started right up. What could be causing this?