Anybody and everybody can and does get enthusiastic about their finances and investments when things are going well. When things are not going so well - when the markets seem to be implementing a personal vendetta against you and you get hit by a seemingly endless stream of unexpected or larger than expected expenses - people tend to lose interest.
It is human nature to devote more attention to successes than to failures. You could call it the emotional equivalent of cutting your losses and letting your winners run.
It's also something in the nature of a character flaw that can and should be remedied.
Adverse market conditions and bad investments are a fact a life. Even Warren Buffet gets things wrong from time to time. One of the things that keeps me focused when my investments are heading south is the knowledge that the market conditions that caused the pain are the same market conditions that provide opportunities to find investments at attractive valuations. Staying focused is exactly what you should be doing at this stage.
A run of expenses or other events that blow the budget - not just for a month but for a whole year? These things also will happen - marriage, children, changing jobs, buying your first home etc. But that is no reason to lose your self discipline. Managing expenses is a life long discipline. When things are going against you is the very time that you should be most focused on extracting as much out of your income as possible.
Staying focused through good times and bad times is an important habit for those looking to achieve financial independence.