Well, must say - finances were a huge hurdle. Took me nearly 5 years to get my CPL / CMIR / ATPL subjects and many odd jobs to save for that next lesson.
Because there were quite a few weeks in between each lesson,
becoming rusty was easy, and therefore very time consuming.
Getting jerked around by instructors all vying for hours into their newly acquired logbooks initially.
Realising that a fair majority of pilots that i've encountered along the way are egotistical D'heads that think their 'God's Gift'. - (It really is quite embarressing being around them at times) :o
Having to make the difficult choice (but the right one in hindsight) to end a relationship after 18 months because she was applying the pressure for marriage. If i ended up married, that meant i could not pursue my intended career (which afterall was my plan from 5yrs of age!)
Travelling around all over the countryside being misled by dubious operators in search of work and taking advantage of you and the current climate of GA. ie- too many pilots / not enough jobs etc etc.
Further realising that, because there are not so many jobs out there, alot of pilots (NOT ALL mind you, i have met a few great one's) are very shallow, selfish and self centred individuals, whom are very friendly to your face. (Beware of those one's kiddies!!!)
I'm sure i'll think of a few more, but it's late and i do have to FLY!
And that's the key - FLY - it's pretty much worth it all in the end. As long as you stick at it, don't be pulled down by the heap of negatives that one encounters along the way, learn from it all, and try to put back into it, the 'good' that hopefully you do have left in you after experiencing it all. (It is easy to become very cynical in this industry.)
Important Note: - If you can 'do unto others as you would have them do unto you', then really - you can't go wrong in aviation, - and LIFE!
KARMA EXISTS !!! and hindsight IS a wonderfull thing!
Oh and BTW, 'PILOTGAL' - how old are you? - roughly?