Hello!
I’ve done a decent amount of research so far but at 25 years old, am I too late in being able to reach the highest goal of being a pilot? For example, being a captain on a 777 at some point in my career? I’m really excited about joining flight school and I want to have my expectations to be realistic.
Jon,
Absolutely not! It may feel late compared to those who did flight training at 18 and regionals by 21 but that’s not the majority! Starting at 25, regionals by 27 and majors by 30 or soon after is actually very normal! You could still have 35+ year career. Definitely enough time to potentially make 777 captain 
-Hannah
Jon,
Not sure where you’ve been researching but the average age for people to start flight training is approx 33yo.
I suggest you visit our FAQ section and do some researching there vs where you’ve been.
Adam
Jon,
I will paint a slightly less optimistic picture than my colleagues here. Everything at the airlines runs on seniority, everything. That means that even aircraft positions are bid on in seniority order and the person who has been there the longest gets first choice, the next the next choice and so on. Some, albeit not many, pilots are already hired at a major by the time they are 25. Most of the ones who are the most senior will be there before they are 30.
The 777 will be Coke cans by the time you are 55 or 60, but whatever the replacement is will be there and it will be a senior airplane. If you start ASAP, you could have a decent shot at being a Captain on whatever its replacement is, but you need to start soon and you need to make choices that will be efficient with your time.
Chris