Actually, this is quite unlikely, as Neptune, even in its supposed 'inaction' and mellowness, is the stronger of the two. Maybe this is the Neptune veil or fog that does not let one see its real power. A conjunction is considered to be the strongest of all aspects in which a fusion, or a complete mixing of energies takes place, and, in the Mars-Nep conjunction, the Neptunian energy dominates. Whilst inner planets have more closely felt, day-to-day, and seemingly direct effects as fast-moving planets; the outers have more long-term, usually irreversible and stronger effects, which usually take time to fully manifest themselves. Neptune has the power to dissolve a lot of that Mars energy, gusto, power to act and agressiveness. It can shroud Mars in its veil of confusion and fog, put its fire out to a large extent, and thereby decapactitate it in a way that Mars cannot act in its full force. This way, it can make Mars quite submissive. Thus, a person with this aspect can feel quite 'lame' and listless, and without energy, drive and the will to put thoughts/plans into action as opposed to a person without this aspect, and a more 'free' Mars, so to speak. A Mars-conj-Nep person can next-to-never be as agressive, overflowing-with-energy-and-passion a person as one without a Nep-Mars aspect. This I have studied often in charts and real life.
aquarius7000