I remember talking to him on the subway in NY (or better saying him talking to me lol) - he is so enthusiastic he almost explodes :-) And I mean that in a very friendly and supportive way. In German I'd call him an "Energiebündel" (bundle of energy, live wire).
During a conversation at an Arabic restaurant he switched between several languages and was always keen to learn something new when I talked to him in German. Of course he makes mistakes and he struggles with some pronunciation issues (I do too by the way in quite a few of the languages I learn) but it is simply a delight watching him communicate with people and when I was in NY I only saw happy faces all around when he was trying to strike up a conversation.
I wish my time management was better but as things stand now I have enough to do with the languages I have learnt so far (with two or three more languages I would still love to learn up to level A2 or so, enough to have a conversation and take it from there). So, what Tim does is indeed fascinating to me. If he were to decide to use his languages professionally, he would have to settle for a smaller number and a higher level of proficiency I guess. But as long as this is not what he aims for, he most likely will keep adding languages and I'll be an interested and supportive observer in his journey.