Adrianus is of course being modest, as in my experience he is a terrific Latinist, especially in terms of his very limpid writing. Holding oneself to the requirements of a Rennaisance university is an extremely high bar, some of their alumns like Lorenzo Valla, Pietro Bembo and I think Pope Pius II could testify.
As for reading CIcero without a dictionary, I have quite a bit of experience reading his prose but I still have to use a dictionary occasionally. For me it’s not an issue of needing the dictionary or not, but how often one needs it, and whether the frequency of unknown words is a significant deterrent to understanding the text. I have to use a dictionary occasionally when reading Rennaisance English authors, so I don’t see why we should seek a higher bar for Latin. In an average oration I might need to look up a couple words on an Oxford Classical Text page, but usually this doesn’t greatly interfere with understanding the speech. If I’m not at my computer, I make a marginal annotation next to the line and look up the word later. I’m experimenting with creating my own Latin marginalia for Ovid’s metamorphoses now which helps retain vocabulary. After reading a number of pages, I go back, reference the vocab I missed, reread the sentence, and then define the unknown word in the margin in other Latin words I know. I’d be interested in hearing about others who have tried something similar.
As for myself, I’ve been studying Latin for almost three years now. The trick to making constant progress is to read read read, not just school assignments, but whatever you can get your hands on whenever you can. I attribute my progress to taking an intensive crash course in Latin grammar, followed by Lingua Latina, followed by copious reading since then. I used to have an hour commute each way on the bus to work. I would print out Latin texts and read and mark them up in the morning and after work. That kind of daily practice is going to be very important.
Certe Adrianus modestus agit, cum latinista, ut dicam, callidus sit, praesertim Latine limpide scribendo. Si desideria univeristatum Renascentiarum persequeris, culmen admodum altum scandere niteris, quoniam qualibus ex universitatibus orti fuerunt homines latine perdocti sicut Laurentius Valla, Pietrus Bembo, et Aeneas Sylvius (Papa Pius II).
De Ciceronem sine vocabulario legendo, mihi etiam rebus Ciceronianis paululum docto interdum vocabulario uti necesse est. Ut dicam, haec non est disputatio anne vocabulario utendum sit, sed quotiens sit necesse atque utrum verba ignota lectioni valde obstent anne. Cum auctores aevi Renascentiae Anglicos legerim, mihi nonnumquam vocabularium consultare oportet, itaque non intelligo cur non ita fiat latine legendo. Oratione Ciceronis aliquâ sumptâ, unâ paginâ Textûs Classici Oxoniensis lectâ me nonnulla verba conferre fieri potest, sed plerumque hoc non lectioni obstat. Si computatrum deest, annotationes in marginem iuxta lineam verbum contentem scribo ut postquam ea scrutari reminiscar. Marginalia latina scribere tempto Ovidii Metamorphoses legens, qua ratione melior verborum significationes menti haereant. Nonnulis paginis lectis, verba ignota refero, sententias denuo lego, et ea verba latine definire conor alia mihi nota adhibens. Mihi intersit audire si alios hîc ita legere.
De me ipso, tres fere annos linguam latinam discebam. Secretum est legere legere legere, non solum cum tibi pro scholâ studendum sit, sed etiam semper legendo quandocumque tibi legere vacat. Prosper sum ego cum protinus rudimenta Latinae didicerim, item librum “Lingua Latina” et demum semper latine legi. Olim mihi accidit unam utrimque horam in coenautocinetum omne die degere, atque aliquid latine, quod prius computro transcrisperat, legebam necnon annotabam. Ita tibi faciendum est si velis optime latine procedere.