Some thoughts on the prefix...

Start by taking SEA (what's left after taking the salt), and then using my MIND. But for MIND, "it's barely after 3", so take only the D. Wrap it all up - so maybe wrap SEA around D, giving SEDA, but this looks weird, so I'm not sure this is prefix quite yet.

EDIT: Continuing to try and solve this

Prefix:

Breakfast was quite delicious, only the salt (NA) didn't get used
Taking what's left (literally) -> N
Then use our MIND (but only take the first 3 letters) -> MIN
Wrap it together -> MINN

Infix:

"X" marks the spot! but to make it fit, we'll say it's EX

Suffix:

I propose you're looking for whatever's NEXT (making the word MINNEXT) It's hard to find what's next, and if you're at the front of the line, you're next

So you may be

A minnow!
Once you find what's next, you're doing it NOW, so replace NEXT with NOW
and you get MINNOW :)

First Guess

Some thoughts on the prefix...

Start by taking SEA (what's left after taking the salt), and then using my MIND. But for MIND, "it's barely after 3", so take only the D. Wrap it all up - so maybe wrap SEA around D, giving SEDA, but this looks weird, so I'm not sure this is prefix quite yet.

Second Guess

Prefix:

Breakfast was quite delicious, only the salt (NA) didn't get used
Taking what's left (literally) -> N
Then use our MIND (but only take the first 3 letters) -> MIN
Wrap it together -> MINN

Infix:

"X" marks the spot! but to make it fit, we'll say it's EX

Suffix:

I propose you're looking for whatever's NEXT (making the word MINNEXT) It's hard to find what's next, and if you're at the front of the line, you're next

So you may be

A minnow!
Once you find what's next, you're doing it NOW, so replace NEXT with NOW
and you get MINNOW :)

Third Guess
Prefix:

Taking what's left over from the sea salt - salt -> C
Using what's within our mind -> IN
(I'm afraid I still don't quite understand the "barely after 3" part)
Combine to get CIN

Infix:

"X" marks the spot

Suffix:

With Hint 3, it sounds like the suffix could be CHANGE. Those with big dreams want to create change (in the industry, for their life, etc); naive youngsters believe they can change the world; politicians promise change (like tax cuts), but seldom follow through.

Altogether:

CINEXCHANGE

Some thoughts on the prefix...

Start by taking SEA (what's left after taking the salt), and then using my MIND. But for MIND, "it's barely after 3", so take only the D. Wrap it all up - so maybe wrap SEA around D, giving SEDA, but this looks weird, so I'm not sure this is prefix quite yet.

Some thoughts on the prefix...

Start by taking SEA (what's left after taking the salt), and then using my MIND. But for MIND, "it's barely after 3", so take only the D. Wrap it all up - so maybe wrap SEA around D, giving SEDA, but this looks weird, so I'm not sure this is prefix quite yet.

EDIT: Continuing to try and solve this

Prefix:

Breakfast was quite delicious, only the salt (NA) didn't get used
Taking what's left (literally) -> N
Then use our MIND (but only take the first 3 letters) -> MIN
Wrap it together -> MINN

Infix:

"X" marks the spot! but to make it fit, we'll say it's EX

Suffix:

I propose you're looking for whatever's NEXT (making the word MINNEXT) It's hard to find what's next, and if you're at the front of the line, you're next

So you may be

A minnow!
Once you find what's next, you're doing it NOW, so replace NEXT with NOW
and you get MINNOW :)