Basically this, I 6 month back pack, did a 20 odd day contiki at the start to get a feel for things then solo the rest. By the end the contiki was the part I least enjoyed. Too many bogan aussies.I have travelled around Europe solo. If anything, travelling solo works better for less extroverted, more introverted people who prefer their own space and are more introspective. You can have your time, staring into space and engaging with your own thoughts. I'm extremely introverted, as in I'm comfortable being on my own for hours, days etc. That's why I prefer to travel solo so I can travel at my own pace. Not to mention you aren't around other tourists all the time and can actually absorb yourself into the foreign environment and engage with locals, rather than hang out with a group of other travellers and people you usually would hang out with at home. I travel solo and stay at hostels, so I can get the best of both worlds. I travel during the day at my own pace and then spend the night hanging out with other travellers at the hostel or bars/pubs etc.
Travel during the day or get night trains and sleep, see the wonders of the town/city and party with the other hostel folk at night.