While I understand what you are getting at, with respect I disagree. I have issues with both myself and other people when it comes to both stocks and real estate.
With real estate, the issue with myself is making a poor assessment either at the time I buy (over valuing the property or misreading the market conditions generally) or when setting an asking rent on a vacant property (too high and the vacancy period will be longer, too low and I am short changing myself). Obviously, tenants and agents can be a pain at times.
With stocks, I have plenty of issues with people - intermediaries wh chanrge too much, incompetent or crooked company directors among others. On the other hand, my own emotions and over/under confidence are my biggest enemies when it comes to stock selection (both buy and sell side).
Budgeting is a skill practised by people who are bad at politics.