You know you overbuilt your rocket when...

[GiantTank]

When on your return from doing the Jool 5 mission you see that you have enough fuel to do it again.

With monoprop only.

[Kendrick]

when your mining platforms demand daily walkies beyond the confines of the launch pad before they do their dutiful digging.

https://youtu.be/F3oN5JM4QXQ

[Coga19000]

When Jebadiah hijacks your suborbital tourist ferry and is like "Wanna get the time of your life, guys? It ain't gonna cost you extra " and then he gets the lucky (?) tourists a flyby of Eve.

[Wallace]

When you finish your mission to Minmus and then decide to send the probe to Jool as an encore.

[vicwarrior]

When you use the "flea" as a separatron because separatrons don't have enough power to push spent stages out of the way.

[sj176]

When you explode by loading to the Launchpad.

[bigyihsuan]

When reentry heating kills the craft when ascending.

[KatzOhki]

You only ditch your ascent stage and transfer stage because they are in the way of your landing gears.

[Joshwoo70]

your rocket looks like whack job's rockets...

@katz we posted at the same time!? What is dis??

[KatzOhki]

It's fate

[Capt. Hunt]

...when the same rocket you designed for a mun shot can take a ship to Jool and back.

(actually, I managed to do that with FASA's Saturn V once, just by stripping out the LEM, but I've also managed it with ships of my own creation too.)

Edited May 11, 2015 by Capt. Hunt

[zekes]

When your rocket can lift other rockets.

[Feradose]

When your payload fairings transfer a big amount of atmosphere to LKO

[Alchemist]

When your usual Munar lander can land on Tylo. (Yes, that's how I landed there the first time. It didn't have enough for getting back up, though)

[Warzouz]

When I did my Jool mission (in beta 0.9 - science game mode) I had a space station to be assembled around Laythe. The 13 parts had to be shipped separatly for a total of more than 400T and 900 parts (payload).

I had a launch stage and a interplanetarly stage. I ditched the remains of the launch stage of some of the parts (well, the lighter ones) in Laythe orbit... If I had been in Carrer game mode, I would had paid nearly 7 000 000 funds for this mission.

I explored all moons twice (+ a flyby). I even had 2 landers for Tylo, no knowing if my SSTO would succeed, I had a backup (lander and pilot ).

When the crew went back in the return vehicle with 41000 science points, I had 3 orange tanks left out of 6 at the station.

[Gravaar]

When your rocket exceeds 25000 tons on the launchpad

[Acemcbean]

... you have have well over 50 stages

[vicwarrior]

My Munlander MK2 (designed to land 3 kerbals at either of kerbin's moons) is so overbuilt it actually became my training rocket as it could get 3 kerbals to level 3 in a single launch by, peeking out of kerbin SOI for sun orbit, landing on minimus, everyone plants a flag, going to the mun, landing, planting another 3 flags and returning home with just enough fuel, just recently did calculations and for level 3 i just need to orbit the mun so now new rookies dont suffer the risk of having to get out and push to lower the periapsis the last few Kms when returning home.

[pslytely psycho]

When you can heat your room, in winter, in the Pacific Northwest, with your water cooled processor, during your 4 hour, 2 fpm launch....

[Teutooni]

When you take your spaceplane for a stability test flight, reach orbit, see that you can reach Minmus and land there. Then you notice you still have 36 tons of fuel as payload, unlock it and do a flyby of Laythe.

[Findthepin1]

"Sir, our solar panels have broken off. It looks like something hit them."

"Sir, we just lost contact with Gilly Stations Alpha thru Delta."

[Windspren]

When you use the Orion nuclear pulse drive as a sepetron for your boosters.

[Lord Aurelius]

When your munar flyby results in the Mun being captured by your rocket.

Edited May 12, 2015 by Lord Aurelius

[Bev7787]

When your "LKO orbit satellite and srb launcher" has the ability to launch into a polar orbit with an orbital scanner, then head to the Mun and polar orbit there.

[Overlocker]

When you use a massive SpaceY SSTO lifter to get into orbit a full StarLifter (the one with from the pics from FTT thread) with full metalic ore cargo. (Actually the Freighter mass is 5000+ tons)

Edited May 14, 2015 by Overlocker