In certain locations and in certain time periods, your ancestor can do things without having generated any paperwork.
Do not assume that there will always be a birth record, a death record, an obituary, a probate, etc. There were times where people of certain social standing, economic classes, ethnic groups, distance from the records office, etc. were not recorded in certain records. Not everyone has an obituary.
Document your search for these items. If you cannot find one, try and see if you can determine the reason.
But–not everyone always generates a record for every vital event in their life.