When I was a young child I wanted to be a truck driver because I spoke to them on the CB all day that was my internet and had a lot of fun. It sounded like a cool career to me at the time but then I found out what their lives were really like. Then when I was a teen I wanted to be a cop. I volunteered thousands of hours to the local PD. Then LAPD said one line that made me think long and hard about it. "We have new positions opening every day" and I knew I would have to start with them unless I could get the local PD to sponsor me and I knew what that phrase really meant, so I fell back on tech which was just a fun hobby for me.
I'm glad I gave up on those things.
[Edit] Oh yeah, and when I was a child I wanted to be a Jedi. It wasn't until the prequels much later in life that I found out I was missing the midichlorian's.
In a broader sense, I think letting go of dreams is extremely important for success.
Create an "unbucket" list for the side quests that detract from the main quests: