Here's one way to keep perspective. It helps to have goals set (and kept in front of you) that work to remind you constantly of where you're going, so you don't get sidetracked by the various little things that happen on a daily basis. One method often used to formulate these goals is known as "SMART goals:"
S = Specific
M = Measurable
A = Attainable
R = Realistic
T = Timely
...so in other words, "I will do very well someday" would not qualify as a SMART goal because it's not specific enough (I will make $X), measurable enough (quantifiable in money or time), attainable (how does one attain "very well?"), realistic (there may be speed bumps along the way and it's hard to jump to "some day"), or timely ("someday" of course isn't really set in terms of time). A better example would be something like
Within six months (timely), my business (specific) will be operating on a break-even basis (realistic- I'm not looking to make a million overnight) (measurable). Is this goal attainable? I don't know yet, but I think it might be. As a result, I might use this as a goal, and adjust it as time goes by.